[FLINK-34108][table] Add built-in URL_ENCODE and URL_DECODE function.

[superdiaodiao]

What is the purpose of the change

issue: https://issues.apache.org/jira/browse/FLINK-34108

This is an implementation of URL_ENCODE and URL_DECODE

1. URL_ENCODE: Translates a string into 'application/x-www-form-urlencoded' format using a specific encoding scheme(UTF-8).
2. URL_DECODE: Decodes a string in 'application/x-www-form-urlencoded' format using a specific encoding scheme(UTF-8).

Brief change log

1. URL_ENCODE

• Syntax:
  url_encode(url)

• Arguments:
  url: a string represents a URL

• Returns:
  translates a string into 'application/x-www-form-urlencoded' format using a specific encoding scheme(UTF-8), will be null if input is null or encode failed.

• Examples:

url = 'https://flink.apache.org/'
SQL: url_encode(url)
TableAPI: url.urlEncode()

output: 'https%3A%2F%2Fflink.apache.org%2F'

2. URL_DECODE

• Syntax:
  url_decode(value)

• Arguments:
  value: a URL encoded

• Returns:
  decodes a string in 'application/x-www-form-urlencoded' format using a specific encoding scheme(UTF-8), will be null if input is null or decode failed.

• Examples:

value = 'https%3A%2F%2Fflink.apache.org%2F'
SQL: url_decode(value)
TableAPI: value.urlDecode()

output: 'https://flink.apache.org/'

Verifying this change

• This change added tests in UrlFunctionITCase.

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): (no)
• The public API, i.e., is any changed class annotated with @Public(Evolving): (no)
• The serializers: (no)
• The runtime per-record code paths (performance sensitive): (no)
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Kubernetes/Yarn, ZooKeeper: (no)
• The S3 file system connector: (no)

Documentation

• Does this pull request introduce a new feature? (yes)
• If yes, how is the feature documented? (docs)

[flinkbot]

CI report:

• 3eab150 Azure: SUCCESS

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[superdiaodiao]

@flinkbot run azure

[snuyanzin]

Thanks for your contribution @superdiaodiao ,
I left some comments

also ci is failed and i tend to think it is related to your changes in python code, could you please have a look?

[superdiaodiao]

Thanks for your contribution @superdiaodiao , I left some comments

also ci is failed and i tend to think it is related to your changes in python code, could you please have a look?

Thanks for your review, it helps a lot.
I will continue to check the python part.

[superdiaodiao]

@flinkbot run azure