Joystick button mapping does not consider firmware support

[ES-Alexander]

Bug description

Cockpit only defines the set of button functions and parameter names used by ArduSub, but it provides them for selection to any connected vehicle, regardless of firmware type.

Steps to reproduce

1. Flash a non-ArduSub firmware onto a flight controller board (e.g. ArduRover on a BlueBoat)
2. Connect to Cockpit
3. Connect a joystick
4. Try to map a button function
5. There is an extensive set of MAVLink Manual Control options provided
   • At best these will do nothing
   • At worst they will have a different meaning defined in the autopilot, and have undefined and potentially dangerous behaviour

Primary pain point(s)

This is unintuitive, and leads to users being confused about what is and isn't supported in the configuration they're trying to set up. It is also a safety hazard.

We should hide options we don't expect to work, and ideally also add support for additional options that are expected to work.

Additional context

Raised while considering this forum thread.

Prerequisites

• I have checked to make sure that a similar request has not already been filed or fixed.