Port QQuickGeoCoordinateAnimation 'to' and 'from' to new bindable properties

These properties are tricky because of the following questions:

• The current implementation reuses the properties of the base class (QQuickPropertyAnimation), but has custom setters and getters, so we can't simply forward the calls to the base implementation.
• The base implementation uses QVariant to store the properties, while QQuickGeoCoordinateAnimation uses QGeoCoordinate. Currently we can't handle such type mismatch.

I suggest to postpone these properties at least until the properties of the base class are updated.