Error handling for global legal search

[johnnyporkchops]

Summary

• Handle server errors:
  • When any FEC legal endpoints are not responding or returning an error (combined legal and rulemakings)
  • When ECFR (Regulations) is not responding or returning an error (check line 27 of ecfr_caller.py for existing error handling that we may be able to build upon)
• See related PR [PR TO 05/13/25 RELEASE] Error handling and logging for global and policy searches #6581

Completion Criteria:

• Users get a message rather than a 500 Server Error page when endpoints are not responding or returning an error
• Logging is implemented to help more quickly determine cause of error

Related Issue:
Global legal search enhancements Issue 6990