event catalog:
- `hdb_catalog` is no longer automatically created
- catalog is initialised when the first event trigger is created
- catalog initialisation is done during the schema cache build, using `ArrowCache` so it is only run in response to a change to the set of event triggers
event queue:
- `processEventQueue` thread is prevented from starting when `HASURA_GRAPHQL_EVENTS_FETCH_INTERVAL=0`
- `processEventQueue` thread only processes sources for which at least one event trigger exists in some table in the source
Co-authored-by: Anon Ray <616387+ecthiender@users.noreply.github.com>
GitOrigin-RevId: 73f256465d62490cd2b59dcd074718679993d4fe