uxrce: add actuator_armed and estimator_gps_status topic publishers

[mehmetkillioglu]

Changelog:

Add following topics to microxrce publishers. Both topics are low frequency, shouldn't add much load. If the usage gets problematic, we can drop EstimatorGpsStatus as it is only used for the diagnostic view.

• ActuatorArmed -> used for determining the kill switch status from manual_lockdown flag
• EstimatorGpsStatus -> used for gps diagnostics. Using checks_passed and check_fail_gps_fix.