wasm: qwebsocketserver hangs

When I try QWebSocketServer, the app freezes.

There is also this message:

QNativeSocketEngine::initialize unable to inline out-of-band data

Which points to the server on webassembly platform is using QTcpServer.

We can either fix QTcpServer for webassembly (by using a platform backend that directly uses WebSockets to mimic a server), and/or fix QWebSocketServer to use WebSockets backend.