close CLOUD-220
<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit
- **New Features**
- Introduced a new service to handle indexing-related events and scheduled tasks, improving the management of document and workspace indexing.
- Added support for configuring the indexer feature via the AFFINE_INDEXER_ENABLED environment variable.
- **Bug Fixes**
- Ensured that indexing and deletion jobs are only enqueued when the indexer feature is enabled.
- **Tests**
- Added comprehensive tests for the new indexing event service, covering various configuration scenarios.
- Removed obsolete test related to auto-indexing scheduling.
- **Chores**
- Updated configuration descriptions and mappings to improve clarity and environment variable support.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
DarkSky