Refactor event system and add third-party event listeners

- Move event_bus import to correct module paths
- Introduce BaseEventListener abstract base class
- Add AgentOpsListener for third-party event tracking
- Update event listener initialization and setup
- Clean up event-related imports and exports

tests/utilities/test_events.py

@@ -1,5 +1,4 @@
 from datetime import datetime
-from unittest import mock
 from unittest.mock import patch
 
 import pytest