Changed HashMap to LinkedHashMap for deterministic order (description,value,key)

[RugvedB]

Note: This PR fixes all the tests failures (19) mentioned in PR: https://github.com/mock-server/mockserver/pull/1817/files in addition to the test failures(8) mentioned in this PR i.e total tests fixed = 27

Created this PR to fix 8 flaky tests listed as follows:

1. shouldSerialiseForwardedRequests
2. shouldSerialiseEventsWithRequestFilter
3. shouldSerialiseRollUpEventsWithCorrelationId
4. shouldSerialiseRecordedRequestsEventsWithoutFields
5. shouldSerialiseEventsWithNoRequestFilter
6. shouldSerialiseForwardedRequestsForEventsWithoutFields
7. shouldSerialiseEventsAndIgnoreDeletedLogEvents
8. shouldSerialiseRecordedRequests

---

1. How were these test identified as flaky?
   These tests were identified as flaky by using an open-source research tool named NonDex which is responsible for finding and diagnosing non-deterministic runtime exceptions in Java programs.

2. What was the error?
   The error was caused by non-deterministic ordering of keys in the entry map here and here. The tests were asserting the exact order of keys in the generated JSON in the following order: description, value, key. Since the implementation was using a HashMap to create the entry map, the order of keys was not guaranteed, leading to different orders during test execution.

Common Error among all the tests mentioned below - jumbled ordering of entry map's keys (i.e description, value, key) in the json:

Expected: is "{\n  \"logMessages\" : [ {\n    \"key\" : \"1a9d2b00-e37e-464f-91df-86c5167bf816_log\",\n    \"value\" : {\n      \"description\" : \"11-27 13:05:49.318 FORWARDED_REQUEST   \",\n      \"style\" : {\n        \"paddingBottom\" : \"4px\",\n        \"whiteSpace\" : \"nowrap\",\n        \"overflow\" : \"auto\",\n        \"color\" : \"rgb(152, 208, 255)\",\n        \"paddingTop\" : \"4px\"\n      },\n      \"messageParts\" : [ {\n        \"key\" : \"1a9d2b00-e37e-464f-91df-86c5167bf816_0msg\",\n        \"value\" : \"messageFormatFour\"\n      } ]\n    }\n  }, {\n    \"key\" : \"34773a6e-987a-488f-b4a7-60772b5d02e3_log\",\n    \"value\" : {\n      \"description\" : \"11-27 13:05:49.318 FORWARDED_REQUEST   \",\n      \"style\" : {\n        \"paddingBottom\" : \"4px\",\n        \"whiteSpace\" : \"nowrap\",\n        \"overflow\" : \"auto\",\n        \"color\" : \"rgb(152, 208, 255)\",\n        \"paddingTop\" : \"4px\"\n      },\n      \"messageParts\" : [ {\n        \"key\" : \"34773a6e-987a-488f-b4a7-60772b5d02e3_0msg\",\n        \"value\" : \"messageFormatThree\"\n      } ]\n    }\n  }, {\n    \"key\" : \"83b73925-6179-4a94-b703-22aca2677438_log\",\n    \"value\" : {\n      \"description\" : \"11-27 13:05:49.318 FORWARDED_REQUEST   \",\n      \"style\" : {\n        \"paddingBottom\" : \"4px\",\n        \"whiteSpace\" : \"nowrap\",\n        \"overflow\" : \"auto\",\n        \"color\" : \"rgb(152, 208, 255)\",\n        \"paddingTop\" : \"4px\"\n      },\n      \"messageParts\" : [ {\n        \"key\" : \"83b73925-6179-4a94-b703-22aca2677438_0msg\",\n        \"value\" : \"messageFormatTwo\"\n      } ]\n    }\n  }, {\n    \"key\" : \"76af75f7-12ac-49da-9790-f05f65b991b0_log\",\n    \"value\" : {\n      \"description\" : \"11-27 13:05:49.315 FORWARDED_REQUEST   \",\n      \"style\" : {\n        \"paddingBottom\" : \"4px\",\n        \"whiteSpace\" : \"nowrap\",\n        \"overflow\" : \"auto\",\n        \"color\" : \"rgb(152, 208, 255)\",\n        \"paddingTop\" : \"4px\"\n      },\n      \"messageParts\" : [ {\n        \"key\" : \"76af75f7-12ac-49da-9790-f05f65b991b0_0msg\",\n        \"value\" : \"messageFormatOne\"\n      } ]\n    }\n  } ],\n  \"proxiedRequests\" : [ {\n    \"description\" : \"   four\",\n    \"value\" : {\n      \"httpRequest\" : {\n        \"path\" : \"four\"\n      },\n      \"httpResponse\" : {\n        \"statusCode\" : 200,\n        \"reasonPhrase\" : \"OK\",\n        \"body\" : \"four\"\n      }\n    },\n    \"key\" : \"1a9d2b00-e37e-464f-91df-86c5167bf816_proxied\"\n  }, {\n    \"description\" : \"  three\",\n    \"value\" : {\n      \"httpRequest\" : {\n        \"path\" : \"three\"\n      },\n      \"httpResponse\" : {\n        \"statusCode\" : 200,\n        \"reasonPhrase\" : \"OK\",\n        \"body\" : \"three\"\n      }\n    },\n    \"key\" : \"34773a6e-987a-488f-b4a7-60772b5d02e3_proxied\"\n  }, {\n    \"description\" : \"    two\",\n    \"value\" : {\n      \"httpRequest\" : {\n        \"path\" : \"two\"\n      },\n      \"httpResponse\" : {\n        \"statusCode\" : 200,\n        \"reasonPhrase\" : \"OK\",\n        \"body\" : \"two\"\n      }\n    },\n    \"key\" : \"83b73925-6179-4a94-b703-22aca2677438_proxied\"\n  }, {\n    \"description\" : \"    one\",\n    \"value\" : {\n      \"httpRequest\" : {\n        \"path\" : \"one\"\n      },\n      \"httpResponse\" : {\n        \"statusCode\" : 200,\n        \"reasonPhrase\" : \"OK\",\n        \"body\" : \"one\"\n      }\n    },\n    \"key\" : \"76af75f7-12ac-49da-9790-f05f65b991b0_proxied\"\n  } ]\n}"
     but: was "{\n  \"logMessages\" : [ {\n    \"key\" : \"1a9d2b00-e37e-464f-91df-86c5167bf816_log\",\n    \"value\" : {\n      \"description\" : \"11-27 13:05:49.318 FORWARDED_REQUEST   \",\n      \"style\" : {\n        \"paddingBottom\" : \"4px\",\n        \"whiteSpace\" : \"nowrap\",\n        \"overflow\" : \"auto\",\n        \"color\" : \"rgb(152, 208, 255)\",\n        \"paddingTop\" : \"4px\"\n      },\n      \"messageParts\" : [ {\n        \"key\" : \"1a9d2b00-e37e-464f-91df-86c5167bf816_0msg\",\n        \"value\" : \"messageFormatFour\"\n      } ]\n    }\n  }, {\n    \"key\" : \"34773a6e-987a-488f-b4a7-60772b5d02e3_log\",\n    \"value\" : {\n      \"description\" : \"11-27 13:05:49.318 FORWARDED_REQUEST   \",\n      \"style\" : {\n        \"paddingBottom\" : \"4px\",\n        \"whiteSpace\" : \"nowrap\",\n        \"overflow\" : \"auto\",\n        \"color\" : \"rgb(152, 208, 255)\",\n        \"paddingTop\" : \"4px\"\n      },\n      \"messageParts\" : [ {\n        \"key\" : \"34773a6e-987a-488f-b4a7-60772b5d02e3_0msg\",\n        \"value\" : \"messageFormatThree\"\n      } ]\n    }\n  }, {\n    \"key\" : \"83b73925-6179-4a94-b703-22aca2677438_log\",\n    \"value\" : {\n      \"description\" : \"11-27 13:05:49.318 FORWARDED_REQUEST   \",\n      \"style\" : {\n        \"paddingBottom\" : \"4px\",\n        \"whiteSpace\" : \"nowrap\",\n        \"overflow\" : \"auto\",\n        \"color\" : \"rgb(152, 208, 255)\",\n        \"paddingTop\" : \"4px\"\n      },\n      \"messageParts\" : [ {\n        \"key\" : \"83b73925-6179-4a94-b703-22aca2677438_0msg\",\n        \"value\" : \"messageFormatTwo\"\n      } ]\n    }\n  }, {\n    \"key\" : \"76af75f7-12ac-49da-9790-f05f65b991b0_log\",\n    \"value\" : {\n      \"description\" : \"11-27 13:05:49.315 FORWARDED_REQUEST   \",\n      \"style\" : {\n        \"paddingBottom\" : \"4px\",\n        \"whiteSpace\" : \"nowrap\",\n        \"overflow\" : \"auto\",\n        \"color\" : \"rgb(152, 208, 255)\",\n        \"paddingTop\" : \"4px\"\n      },\n      \"messageParts\" : [ {\n        \"key\" : \"76af75f7-12ac-49da-9790-f05f65b991b0_0msg\",\n        \"value\" : \"messageFormatOne\"\n      } ]\n    }\n  } ],\n  \"proxiedRequests\" : [ {\n    \"key\" : \"1a9d2b00-e37e-464f-91df-86c5167bf816_proxied\",\n    \"description\" : \"   four\",\n    \"value\" : {\n      \"httpResponse\" : {\n        \"statusCode\" : 200,\n        \"reasonPhrase\" : \"OK\",\n        \"body\" : \"four\"\n      },\n      \"httpRequest\" : {\n        \"path\" : \"four\"\n      }\n    }\n  }, {\n    \"value\" : {\n      \"httpResponse\" : {\n        \"statusCode\" : 200,\n        \"reasonPhrase\" : \"OK\",\n        \"body\" : \"three\"\n      },\n      \"httpRequest\" : {\n        \"path\" : \"three\"\n      }\n    },\n    \"description\" : \"  three\",\n    \"key\" : \"34773a6e-987a-488f-b4a7-60772b5d02e3_proxied\"\n  }, {\n    \"description\" : \"    two\",\n    \"key\" : \"83b73925-6179-4a94-b703-22aca2677438_proxied\",\n    \"value\" : {\n      \"httpRequest\" : {\n        \"path\" : \"two\"\n      },\n      \"httpResponse\" : {\n        \"statusCode\" : 200,\n        \"reasonPhrase\" : \"OK\",\n        \"body\" : \"two\"\n      }\n    }\n  }, {\n    \"value\" : {\n      \"httpRequest\" : {\n        \"path\" : \"one\"\n      },\n      \"httpResponse\" : {\n        \"statusCode\" : 200,\n        \"reasonPhrase\" : \"OK\",\n        \"body\" : \"one\"\n      }\n    },\n    \"description\" : \"    one\",\n    \"key\" : \"76af75f7-12ac-49da-9790-f05f65b991b0_proxied\"\n  } ]\n}"

10. What is the fix?
    To address the non-deterministic order of keys, I replaced the usage of HashMap with LinkedHashMap when creating the entry map. Unlike HashMap, LinkedHashMap preserves the order of keys based on their insertion order. By explicitly ordering the keys in the style map according to the expected order, we can ensure consistent ordering during each test run. This PR proposes changing HashMap to LinkedHashMap here and here and adding elements to style map in the expected order to fix all the listed tests.

---

You can run the following commands to run the 8 tests using NonDex tool respectively:

mvn -pl mockserver-netty edu.illinois:nondex-maven-plugin:2.1.1:nondex -Dtest=org.mockserver.dashboard.DashboardWebSocketHandlerTest#shouldSerialiseForwardedRequests

mvn -pl mockserver-netty edu.illinois:nondex-maven-plugin:2.1.1:nondex -Dtest=org.mockserver.dashboard.DashboardWebSocketHandlerTest#shouldSerialiseEventsWithRequestFilter

mvn -pl mockserver-netty edu.illinois:nondex-maven-plugin:2.1.1:nondex -Dtest=org.mockserver.dashboard.DashboardWebSocketHandlerTest#shouldSerialiseRollUpEventsWithCorrelationId

mvn -pl mockserver-netty edu.illinois:nondex-maven-plugin:2.1.1:nondex -Dtest=org.mockserver.dashboard.DashboardWebSocketHandlerTest#shouldSerialiseRecordedRequestsEventsWithoutFields

mvn -pl mockserver-netty edu.illinois:nondex-maven-plugin:2.1.1:nondex -Dtest=org.mockserver.dashboard.DashboardWebSocketHandlerTest#shouldSerialiseEventsWithNoRequestFilter

mvn -pl mockserver-netty edu.illinois:nondex-maven-plugin:2.1.1:nondex -Dtest=org.mockserver.dashboard.DashboardWebSocketHandlerTest#shouldSerialiseForwardedRequestsForEventsWithoutFields

mvn -pl mockserver-netty edu.illinois:nondex-maven-plugin:2.1.1:nondex -Dtest=org.mockserver.dashboard.DashboardWebSocketHandlerTest#shouldSerialiseEventsAndIgnoreDeletedLogEvents

mvn -pl mockserver-netty edu.illinois:nondex-maven-plugin:2.1.1:nondex -Dtest=org.mockserver.dashboard.DashboardWebSocketHandlerTest#shouldSerialiseRecordedRequests

Test Environment:

java version 11.0.19
Apache Maven 3.9.5

Kindly let me know if this fix is acceptable.
Thank you