Fix showPanel calls

Prevent view switching apis support a stack

Add view switch prevention

Fix textRole usage for QGCComboBox

Make scrollable, fix broken combobox

Enable ArduPilot motor testing

Fix mad merge

Adjust merge to Stable code

Support up to 64 buttons, not limit to 16
Send a single button command and not a stream of commands at 25Hz
Send button commands through signals (it's coming from a different thread)
Hide gimbal support through analog channels (there are no MAVLink messages to handle it)

FMUK66 updates

Map gimbal controls
Keep track of gimbal position within Vehicle

Add gimbal to external control signal

Add camera trigger
Add video start/stop/toggle recording
Add gimbal pitch and yaw

Add .apj file picker support

With the switch to QtQuick, all file dialogs from the c++ side no longer work. This was marked as TODO and fell through the cracks.

Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>

Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>