Add support for fetching prefill values from ATS system when task_assignment_id parameter is provided. This includes:
- New ATS API integration in PrefillFieldsHelper to fetch prefill values
- Cache layer for ATS prefill values with 30-minute TTL
- Merge logic to respect existing submitter values over ATS prefill values
- Error handling and logging for ATS API failures
- Integration with SubmitFormController to fetch values before form rendering
The feature allows forms to be pre-populated with candidate data from the ATS system while preserving any values already entered by submitters.
Bernardo Anderson