Instead of maintaining a seperate latitude/longitude values
in C++ and passing them to QML separatelly, pass them as a QGeoCoordinate.
This reduces the number of model "roles" and also prevents the creations
of extra objects in QML (e.g. via QtPositioning.coordinate(..)).
Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>