feat(transport): implement 0-RTT methods

[achyuthcodes30]

Description

Implement QUIC 0-RTT (zero-round-trip) handshake support in zaprpc, allowing clients to initiate RPC requests immediately on resumed sessions!

QUIC 0-RTT allows previously authenticated clients to send requests immediately on connection resumption, improving latency for RPC calls.

Expected Work

• Implement the ServeEarly method for Server, using the AcceptEarly method from quic-go and allowing users to opt in to rejection of unsafe early data (eg: non idempotent methods), make sure handleSession is updated accordingly
• Implement NewEarlyConn, similar to NewConn, making sure it uses the DialEarly method from quic-go and TLS Session Resumption is opted in for by the user with TLS ClientSessionCache
• If Zap fails with 0-RTT, gracefully fallback to normal handshake

References

• https://quic-go.net/docs/quic/server/
• https://quic-go.net/docs/quic/client/
• https://blog.cloudflare.com/even-faster-connection-establishment-with-quic-0-rtt-resumption/