Maintaining the current queue size in a SQL column would require
updating the DB on every queue operation. Avoid that contention by
instead looking up the current size on the in-memory durable queue
struct, which is already tracked & updated as data enters & leaves
the queue.
* feat: added durable queue management to replications service
* refactor: improved mapping of replication streams to durable queues
* refactor: modified replication stream durable queues to use user-specified engine path
* chore: generated test mocks for replications DurableQueueManager
* chore: add test coverage for replications durable queue manager
* refactor: made changes based on code review, added mutex to durableQueueManager, improved error logging
* chore: ran make fmt
* refactor: further improvements to error logging