[WASM] Not receiving websocket messages

[sabin26]

Describe the bug
WebSocket message is received on VM & JS environments but not on WASM.

i.e. webSocketClient.stream.json or webSocketClient.stream.text or webSocketClient.stream.bytes doesn't emit any data when flutter app is compiled to WebAssembly

Expected behavior
WebSocket message is received.

Desktop (please complete the following information):

• OS: Windows 10
• Browser Chrome

[PlugFox]

Yes, wasm is a pretty fresh compilation target; I'll take a look at that problem in the near future.