feat: throttle Watch<T> and OnChange

[LucDeCaf]

Adds throttling to Watch<T> and OnChange. The first event is emitted immediately upon being received, and any subsequent events that fall in the throttle window are accumulated + deduped until the throttle times out.

Benchmarks

• Using ThrottleMs = 30 (default)
• Watch query: SELECT COUNT(*) AS count FROM assets
• Execute query: INSERT INTO assets (id, description, make) VALUES (uuid(), 'some desc', 'some make')

	Number of Execute calls	Number of events fired to Watch
Unthrottled	1000	1000
Throttled	1000	4
Unthrottled	10000	10000
Throttled	10000	32-35

Tasks

• Throttle core OnRawTableChange function
• Test with OnChange
• Test with Watch
• Test ExecuteBatch behaviour
  • OnChange receives one event post-transaction
  • Watch receives one event post-transaction