Implement websocket client `WsClient`

[armanbilge]

• https://curl.se/docs/websocket.html
• https://curl.se/libcurl/c/curl_ws_recv.html
• https://curl.se/libcurl/c/curl_ws_send.html
• https://curl.se/libcurl/c/curl_ws_meta.html

[hnaderi]

Is anyone working on it? I think I can give it a try this week.

[armanbilge]

Great!

[hnaderi]

I've implemented this in the linked PR, however there are some issues which I think are related to libcurl itself, and I've submitted an issue for in the curl repository.