Why?

Implementing process step per the design in https://github.com/uber/submitqueue/blob/main/doc/rfc/stovepipe/steps/process.md

What?

Storage setup for Stovepipe's new Queue entity:

• Introduce the per-queue coordination store backing the process stage: GetOrCreate, Get, and Update.
• Wire QueueStore into the Storage aggregator and add the queue table schema.
• Include MySQL integration tests for create, idempotent get-or-create, CAS updates, and version mismatch handling.

Test Plan

• Integration tests
• Next few PRs will begin to incorporate this logic and we can test it locally