Use actual API data for QuadcopterModel

I can't really test this though as the API methods aren't implemented
properly yet. Besides, I don't have any Crazyflies here.
Wire up the QuadcopterDetailDialog with the API

The dialog now listens to data changes both via the QuadcopterModel and
directly via APIQuadcopter's listener methods. We might want to remove
one of those in the future (i.e. when the listener methods are actually
implemented and work).