Websocket performance optimization

[lassepe]

By default, HTTP.WebSockets uses a TCP socket configuration that is rather slow:

• In the default setting, HTTP.WebSockets takes about 0.04s to respond to a request from a python websockets client.
• An equivalent python server takes only 0.0002s to respond.

However, if one disables Nagel's algorithm on the tcp socket, the Julia implementation is on par.
In fact, with the tuned socket below I get Julia to 1e-5s response time.

function server()
    server = WebSockets.listen!("127.0.0.1", 8081) do ws
       # without these options below, the socket is way too slow.
        Sockets.nagle(ws.io.io, false)
        Sockets.quickack(ws.io.io, true)

        for msg in ws
            WebSockets.send(ws, msg)
        end
    end
end

Proposal: It would be nice to make this tuning the default and expose some relevent settings via the keywords of HTTP.WebSockets.listen! and HTTP.WebSockets.open.

[lassepe]

Xref: https://brooker.co.za/blog/2024/05/09/nagle.html

[quinnj]

SGTM! Mind making a PR?