[Draft] On Emergency Button hit, send MAV_CMD_ODID_SET_EMERGENCY

[jnomikos]

On Emergency button hit, sends the new MAV_CMD_ODID_SET_EMERGENCY command which was pushed to upstream MAVLink here: mavlink/mavlink#2086

Discussions about it are here: https://github.com/mavlink/mavlink/wiki/20240228-Dev-Meeting
and here: mavlink/mavlink#2027 (comment)

Sends the new MAVLink command MAV_CMD_ODID_SET_EMERGENCY when the emergency button is activated.

NOTE: This is currently a draft because the MAVLink library on QGC needs to be updated to allow for this message to be sent.

Test Steps

1. Ensure successfully builds and runs
2. Flash PX4 firmware which has support of this message (I will also create a draft PR for that, but MAVLink also needs to be updated on PX4)
3. Plug in remote id module with flight controller.
4. Ensure remote ID module is detected on QGC
5. Install a drone scanning app to view the status of the drone
6. Hold the emergency button and see if the status goes to emergency

Checklist:

• Review Contribution Guidelines.
• Review Code of Conduct.
• I have tested my changes.

Related Issue

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[DonLakeFlyer]

How come this is still in development.xml and hasn't moved to common if it has been approved on the MAVLink side of things.

[hamishwillee]

MAVLink only move things across when there is a prototype/proof of implementation and acceptance into flight stacks. Otherwise historically we've ended up with lots of crud in common that never got implemented.

We're not in love with this particular command - it shouldn't have to exist if PX4 implemented automatic setting of emergency states in the remote ID. Its been approved though as the only option for getting this compliance thing into the architecture in time.

[DonLakeFlyer]

Ok, got it