ADSB: uAvionix Transponder Updates

[nicholas-inocencio]

This PR contains updates to the interface with the ping200X in the Transponder tab. Co-requisite with the ArduPilot PR ArduPilot/ardupilot#28419

Changes:

• Fix a display error where the "ON" button was not properly bolded when the transponder mode was set to "ON"
  • It should be bold when the status message indicates mode A, S, and 1090ES are on and mode C is off
• Requests the UAVIONIX_OUT_STATUS mavlink message at 1 Hz when it first gets that same message
  • This enables smarter timeout behavior; see next point
• Make controls/display more responsive to connection errors with the transponder
  • Display "Transponder Offline" when status message is received but the flag UAVIONIX_ADSB_OUT_STATUS_FAULT_STATUS_MESSAGE_UNAVAIL is set.
  • Display "Transponder Status Lost" if the GCS had previously received a UAVIONIX_OUT_STATUS message but 5 seconds pass without seeing another one.
    • This usually happens if the AP is power cycled (thus resetting the UAVIONIX_OUT_STATUS request)

[magicrub]

I just tested this along with the ArduPilot changes and it looks like a good improvement. I'm retesting on Friday and when that merges then we should merge this too

[magicrub]

I've tested this while using PR ArduPilot/ardupilot#28419 and it works much better. Let's merge!