The QML Position type should expose the equivalent QGeoPositionInfo in the C++ API

The C++ API for the QML Coordinate element currently exposes the underlying QGeoCoordinate.

The Camera API would like to make use of the QGeoPositionInfo which corresponds to a QML Position element and can't, because it isn't exposed.

If we make this addition it will add some extra consistency and make things easier for people writing QML elements in C++ that make use of the QML Position.

Since this is a private API it doesn't have much effect beyond that.