Flow network name clarification (#4493)

* network names clarification

* simplify network naming

* add flow testnet for future roll out

* remove newline

* fix linting errors

* add newline at end of file

---------

Co-authored-by: ligi <ligi@ligi.de>

_data/chains/eip155-545.json

@@ -0,0 +1,23 @@
+{
+  "name": "Testnet",
+  "chain": "Flow",
+  "rpc": ["https://testnet.evm.nodes.onflow.org"],
+  "faucets": ["https://testnet-faucet.onflow.org"],
+  "nativeCurrency": {
+    "name": "FLOW",
+    "symbol": "FLOW",
+    "decimals": 18
+  },
+  "infoURL": "https://developers.flow.com/evm/about",
+  "shortName": "flow-testnet",
+  "chainId": 545,
+  "networkId": 545,
+  "icon": "flowevm",
+  "explorers": [
+    {
+      "name": "Flow Diver",
+      "url": "https://testnet.flowdiver.io",
+      "standard": "none"
+    }
+  ]
+}

_data/chains/eip155-646.json

@@ -1,6 +1,6 @@
 {
-  "name": "FlowEVM PreviewNet",
-  "chain": "FlowEVM",
+  "name": "Previewnet",
+  "chain": "Flow",
   "rpc": ["https://previewnet.evm.nodes.onflow.org"],
   "faucets": ["https://previewnet-faucet.onflow.org"],
   "nativeCurrency": {
@@ -9,7 +9,7 @@
     "decimals": 18
   },
   "infoURL": "https://developers.flow.com/evm/about",
-  "shortName": "flowevm-preview",
+  "shortName": "flow-previewnet",
   "chainId": 646,
   "networkId": 646,
   "icon": "flowevm",

_data/chains/eip155-747.json

@@ -1,6 +1,6 @@
 {
-  "name": "FlowEVM Mainnet",
-  "chain": "FlowEVM",
+  "name": "Mainnet",
+  "chain": "Flow",
   "rpc": ["https://mainnet.evm.nodes.onflow.org"],
   "faucets": [],
   "nativeCurrency": {
@@ -9,7 +9,7 @@
     "decimals": 18
   },
   "infoURL": "https://developers.flow.com/evm/about",
-  "shortName": "flowevm-mainnet",
+  "shortName": "flow-mainnet",
   "chainId": 747,
   "networkId": 747,
   "icon": "flowevm",