AP_Mount: gimbal_manager_set_pitchyaw is not a command

[olliw42]

This PR changes the name of the function handle_command_gimbal_manager_set_pitchyaw() to handle_gimbal_manager_set_pitchyaw(), since the underlying MAVLink message is not a command but a message.

The PR grabs the opportunity to also change one access of _mode to get_mode(). All other function in the AP_Mount library call get_mode(), except in this one place.

The PR also does two tiny formattings.

The PR is only cosmetic and nfc. Compiles and very lightly tested.

[olliw42]

oh, wau ... it seems to be extremely difficult for normal mortals to pass the checks. Any hint/help would be much appreciated.

[khancyr]

Motor vibration test shouldn't related to the PR ... Unfortunately, we got some tests that aren't fully deterministic because of SITL or github action... So sometime we got random failure, specially on all fft things...

[olliw42]

many thx for your reponse. I too had a feeling that motor vib stuff shouldn't relate to the PR, but fact is it fails. Not sure I can do anything here, if so pl share. Let's see how this can move on.

[olliw42]

that's a cool reason for the checks to fail: #25445 (though here it's quite obvious what the gps fail is, not so the mot vib fail)
it's the same script as here. It's probably not unfair to say that the tests are a bit sensitive, and that it's not necessarily the submitted code.

[rmackay9]

LGTM, thanks!