Refactor the gateway to properly accept close frames

[kozabrada123]

also introduces a test for receiving the close codes.

Differentiates the wasm and tungstenite gateways a bit more.

The same thing should be done for the voice gateway, I'll likely add it to this pr if the mod to the normal gateway is okay

[bitfl0wer]

// Note: The tungstenite backend handles close codes as messages, while the ws_stream_wasm one handles them differently.

Since I have seen this comment in multiple files now: Would it perhaps be possible and feasible to convert wasm-stream and tungstenite messages into the same type? that way, we would not have to differentiate between the two in multiple files

[kozabrada123]

That's how we used to do it; probably no, unless we have another task that just listens for ws_stream_wasm errors

[kozabrada123]

How the messages are is represented currently: non error messages from tungstenite and ws_stream_wasm can both be RawGatewayMessage. GatewayCommunication are all tungstenite messages

[bitfl0wer]

That's how we used to do it; probably no, unless we have another task that just listens for ws_stream_wasm errors

I meaaaan, that could work!

[kozabrada123]

I think this is nicer
also, multiple files? they are twice in gateway.rs, and then in voice/gateway.rs (which is basically a copy of the former)

[bitfl0wer]

I like these changes! My only issue with them would be what I already mentioned, but other than that it looks great!