Implement networking handlers for Raft

This MR introduces a gRPC transport interface for handling Raft communication. It implements the logic for sending and receiving Raft messages, including packing and unpacking log data. Additionally, the RaftManagerRegistry facilitates Raft manager registration and partition lookup. For the address lookup, we introduce a static routing table for now. In future, the table can be dynamic so that the addresses are propagated through gossiping.

Closes #6401 (closed)