fix: improve performance (#4300)

## Note

This release requires a setup step to fully improve performance.
Be sure to start ZITADEL with an appropriate command (zitadel start-from-init / start-from-setup)

## Changes

- fix: only run projection scheduler on active instances
- fix: set default for concurrent instances of projections to 1 (for scheduling)
- fix: create more indexes on eventstore.events table
- fix: get current sequence for token check (improve reread performance)

cmd/setup/04/postgres/index.sql

@@ -0,0 +1,3 @@
+CREATE INDEX IF NOT EXISTS write_model ON eventstore.events (instance_id, aggregate_type, aggregate_id, event_type, resource_owner);
+
+CREATE INDEX IF NOT EXISTS active_instances ON eventstore.events (creation_date, instance_id);