feat(websocket): add functionality to remove listeners

[nvzeppelin]

Implements functionality to remove listeners from a websocket in frontend. Example usage:

import type WebSocket from "tauri-plugin-websocket-api";
const ws = await WebSocket.connect("wss://example.org");
const listenerId = ws.addListener(handleMessage);;
//do stuff with ws
ws.removeListener(listenerId);

[jffaust]

@nvzeppelin think you can have a look at the merge conflicts?

[nvzeppelin]

I'll close this in favor of #2027 as it's a way cleaner implementation than mine