Use generated Kibana API client for detection rules and add comprehensive tests

- Replace custom HTTP client with generated kbapi client from /generated/kbapi
- Update transform_schema.go to include detection_engine/rules API endpoints
- Regenerate Kibana client with detection rules API support
- Handle proper type conversions for SecurityDetections API types
- Add UUID handling for rule IDs using github.com/google/uuid
- Expand acceptance tests to cover Create, Read, Update, and Delete operations
- Add import state verification test

Co-authored-by: nick-benoit <[email protected]>

Author: Copilot