AP_Mount: send text feedback when gimbal gets detected

[amilcarlucas]

[olliw42]

ideally it would not be send then the gimbal is detected (initialized) but whenever it is "needed"

I do it by linking it to send banner (the banner appears to me to be always send out when e.g. a gcs connects, so it appeared to me to be not too bad, but there might better ways) https://github.com/olliw42/BetaPilot/blob/BetaCopter41/libraries/GCS_MAVLink/GCS_Common.cpp#L3655-L3658 https://github.com/olliw42/BetaPilot/blob/BetaCopter41/libraries/GCS_MAVLink/GCS_Common.cpp#L3655-L3658 just as an idea

[peterbarker]

Ping @amilcarlucas - suggestions have been made here

[rmackay9]

I think @olliw42's suggestion is a good one. If we want the user to reliably see the message then linking to the banner is probably the best way to do it.

So I think the question becomes whether displaying the gimbal info is important enough. Comparing to other subsystems, we do display Servo output info in the banner because we found users were having troubles getting the outputs configured correctly (because the setup is complex) especially when using DShot/BLheli. If we take it to the extreme then every subsystem would display something in the banner which would result in a huge block of text sent to the GCS each time the parameters are downloaded. Maybe that would be useful and maybe then the issue would just become how often it is displayed which is a different issue we could fix as well.

[amilcarlucas]

OK, implemented Randy suggestion and all tests pass

[rmackay9]

Recently we're using GCS_SEND_TEXT more than gcs().send_txt() but I've merged anyway to keep things moving along.