ws: HTTP/2

[niaow]

Currently, the main thing blocking further development is the inability in net/http to set the :protocol pseudo-header

[niaow]

blocked on golang/go#32763

[niaow]

From what I understand, the protocol should be basically the same for HTTP/3, so I think this should also work for HTTP/3

[niaow]

Since we are basically doing the same thing, I am collaborating with @nhooyr on this. Most of the discussion will probably be on coder/websocket#4.