Update WebSocket documentation for Godot 4

[Calinou]

• Salvage of Update WebSocket documentation for Godot 4 #7645. Thanks @TranquilMarmot for the update work 🙂

There's an issue with the minimal client example where it will return garbage data when connected to the minimal server example (it changes on every client start):

Connecting to ws://localhost:9080...
  ERROR: Unicode parsing error, some characters were replaced with � (U+FFFD): Invalid UTF-8 continuation byte (e9 ... 33 ...)
< Got data from server: �]O
> Sending test packet.

This does not occur if you connect to wss://echo.websocket.org. I tested this on all stable versions between 4.0.stable and 4.4.1.stable, and the outcome was the same in each version.

Edit: Fixed the above issue thanks to @Faless.

• This closes Docs Minimal server example outdated on the Networking/WebSocket page. #10031.

[TranquilMarmot]

Awesome, thanks for salvaging! 🫶

[mhilbrunner]

Thanks, all of you! Merged.