[Feature]: Http2 proxy suport

[winchesHe]

What problem does this feature solve?

When use the https and proxy it will auto change to use http/1

What does the proposed API look like?

1. It can support current proxy config
2. One more attr in serverConfig like http2: boolean which can decide if the http2 open
3. Want to use http2-proxy to create a proxy middleware

[winchesHe]

If there is such a requirement, I am willing to implement it

[chenjiahan]

[node-http2-proxy] is not under active development, I'm not sure if adopting it is a good idea.

There are some related discussion:

• nodejitsu/node-http-proxy is dead. Would you consider switching? chimurai/http-proxy-middleware#214
• Support HTTP2 and Proxy at the same time? vitejs/vite#4184
• add http2-proxy support chimurai/http-proxy-middleware#426