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 other ui tweaks