AIRM Conformant

This provides the reason that a flight has been automatically decorrelated:
- FLIGHT_TERMINATED: De-correlation performed when the SFPL flightPlanStatus becomes TERMINATED.

- TRACK_DROP: De-correlation performed upon loss of the system track.

UNEXPECTED_CODE: De-correlation performed when the system track SSR code changes to a code that is not the current SSR code, nor the following SSR code, nor an emergency SSR code.