fix: vehicle fines and insurance sync timeouts and crashes

[MariamMabele]

This update fixes major issues in how we fetch data for vehicle fines (TPF) and insurance cover notes (Tiramis).
Helper Function (vehicle_authority.py):

• Added a smart helper that automatically finds all vehicles, trucks, and trailers in the system by looking for license plate fields. Fines and Insurance Sync (vehicle_fine_record.py & tz_insurance_cover_note.py):
• Moved the syncing process to the background queue. This stops the system from freezing or timing out after 5 minutes when checking hundreds of vehicles.
• Added a check to skip duplicate license plates, so we don't ask the API for the same vehicle twice.
• Automatically cleans up spaces in license plates and skips empty or invalid ones.