Support Kafka API

[vevi]

It would be nice to support existing Kafka client API to leverage the existing Kafka ecosystem.

The goal is to support protocol translation for interoperability, not as a storage format.

Protocol documentation: https://kafka.apache.org/protocol.html

Tasks:

• A: Implement basic Kafka API operations like metadata (3), api versions (18), find coordinator (10) and create topics (19).
• B: Implement Produce (0) operation: decode a record batch, use the key to route and call produce by message.
• C: Implement operations related to fetching/consuming: fetch (1), list offsets (2) and offset commit (8). These requires creating an abstraction for the request writer (currently HTTP only).
• D: Support compression

[jorgebay]

I've created a working branch (82-kafka-api) to understand the complexity of this feature.

I've added some info on this ticket about what needs to be done to support the Kafka API for producing and consuming.