Create a "Dead Mouse Area" control to eat mouse events underneath desired area. This is to prevent mouse events from leaking through controls underneath the area.
Replace original "NoMouseThroughRectangle" as this is more versatile.
Prevent mouse through events from leaking underneath the Fly View tool strip.

Adding missing qgcView to QGCMapPolygonVisuals instance in SurveyMapVisual.qml

Plus various bug fixes from flight testing

Also remove custom gimbal support

Number calc doesn't work so hiding for now

Fix #5812
Show an error message when creating a KML without 2 items at least

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

Converted Structure Scan to use CameraCalc such that it now works with
camera specs.

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

Fix crash when adding second structure scan

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

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

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