[MNT] Deprecation of datetime.utcnow() and improvement of synchronization logic

[MOHITKOURAV01]

Describe the bug / Optimization

Currently, the codebase uses datetime.utcnow() and datetime.utcfromtimestamp() in several core modules. As of Python 3.12, these methods are officially deprecated and can lead to bugs because they return "naive" datetime objects (without timezone info).

Additionally, the current error handling and synchronization logic in synchronization.py and error_handling.py use legacy methods like traceback.print_exc(), which are less effective for production logging.

Proposed Changes

I propose a modernization of the time handling and logging logic:

1. Datetime Modernization: Replace all instances of utcnow() and utcfromtimestamp() with timezone-aware datetime.now(UTC) in:
   • aiod_entry.py
   • bookmark.py
   • Routers and Connectors.
2. Standardized Logging: Update error_handling.py to use logging.exception() for better traceability.
3. Synchronization Refactoring: Use the csv module in synchronization.py to make error reporting more robust and remove redundant logic.
4. Test Updates: Update test_bookmark_endpoints.py to ensure compatibility with timezone-aware objects.

Expected impact

• Future-proof code that is compatible with Python 3.12+.
• More reliable timestamp comparisons in tests and production.
• Better error visibility in logs.

Additional context

I have already verified these changes locally, and all 30 relevant tests in src/tests/ are passing. I am ready to submit a PR for this!