Add missing `.py` extension to Tools/px4 to fix #7525

This is important for multicopters for drift-free altitude changes and important for fixed wing to keep the current loiter center.

This should ensure that controllers run first and log data copying happens after.
;

Sensors: Do not update calibration when armed. Run at lower priority than attitude control and estimator

This ensures that the massive (several hundred params if temperature compensation is enabled) param load is not done in flight. We also lower the priority to ensure that attitude controllers and estimators which might consume sensor data directly execute immediately, which should reduce their latency.

This allows to re-enable the distance trigger and immediately take a picture. This is helpful to ensure survey areas are covered on entry and exit.

Text to speech will work better with these messages and some of them exceeded the 50 character limit.

This increases the chance that the operator gets to see the messages that the vehicle emitted before telemetry was connected.

If we have not received an inbound heartbeat we are probably not connected and so user-facing output (which is even buffered) should go only out once we are connected.

Commander: Do not allow to set mission mode if the mission is failing feasibility checks. Provide clear feedback if telemetry is online and home is set about an invalid mission state.

 - closes #7550

This requires further investigation. Hotfix.