Add overlay getProperty() for text overlay "text" property
Add position vector and color object script value examples

OverlayPropertyResult type is needed to successfully move QScriptValue
objects from QScriptEngine in Overlays to QScriptEngine in script.
Add property getting for all 2D overlays
Add property getting for all 3D overlays
Refactor QRect conversion to QScriptValue
Merge branch 'master' into 20157

Conflicts:
	interface/src/ui/overlays/Text3DOverlay.cpp
Merge pull request #3784 from ctrlaltdavid/20157

CR for Job #20157 - Enable "Get Overlay properties" from javascript