feat(circuit-service): handle driver absence processing and filtering
- Add handleDriverAbsence method to split driver assignments during absence period
- Implement splitAssignmentsForDriverAbsence to create inactive segments for absence periods
- Add createdFromAbsence flag to TripDriverAssignment entity to mark absence-related segments
- Integrate getNonAbsentDriverUuidsForPeriod in driver search to filter available drivers
- Update getAvailableDriversForPeriod to use UUID-based non-absent driver filtering
- Add absence period display in assignment lists (absencePeriod in DTOs)
- Update mapper to populate absencePeriod based on createdFromAbsence flag
- Ensure proper Kafka event publishing for split assignments during absence handling