feat: enhance performance logging and caching in various components

- Introduced slow callback logging in FastAPI to identify blocking calls.
- Added performance logging for agent creation and tool loading processes.
- Implemented caching for MCP tools to reduce redundant server calls.
- Enhanced sandbox management with in-process caching for improved efficiency.
- Refactored several functions for better readability and performance tracking.
- Updated tests to ensure proper functionality of new features and optimizations.

surfsense_backend/tests/conftest.py

@@ -33,4 +33,5 @@ def make_connector_document():
         }
         defaults.update(overrides)
         return ConnectorDocument(**defaults)
+
     return _make