OverviewMapController QML Type
MapView which represents an overview/inset of the current viewpoint of the geoView.
The symbol used to represent the GeoView's current viewpoint.
If OverviewMapController::geoView is not set, then the symbol will return
nullptr by default.
If OverviewMapController::geoView is set, and a custom symbol was not applied, then a default will be provided.
For MapView, the default is an empty SimpleFillSymbol with a 1 point red outline; for SceneView, it will be a red, cross-hair SimpleMarkerSymbol.