[Serve] Rebase Serve to become transparent HTTP/2 proxy to avoid parsing gRPC payloads

[alexeykudinkin]

What happened + What you expected to happen

Currently using gRPC with Serve entails

• Need to provide schemas upfront when Serve is started which makes it impossible to pull it inside Runtime Env
• Incoming request/responses being parsed at the proxy

Instead, we'd just rely on server (uvicorn) to transparently proxy on the application transport layer (HTTP/2) w/o proxy meddling as man-in-the-middle.

Versions / Dependencies

2.22

Reproduction script

N/A

Issue Severity

Medium: It is a significant difficulty but I can work around it.

[alexeykudinkin]

Seems like uvicorn is actually having no plans to support H2 and we might need to move to hypercorn: https://github.com/encode/uvicorn/issues/47#issuecomment-1029020324

[zcin]

@GeneDer could you help triage this

[GeneDer]

yea, sorry didn't know this had the triage tag