Rename AbstractView -> AbstractScene

Consistency++

Change-Id: Ic52e8a5291ac89283009edcfcc11482f92c5f99e
Minor: Remove unneeded Q_INVOKABLEs

Change-Id: Ied7cacb63ff297e8930eab31825731e096c1d816
Fix TODO: Move InstantiatorInterface to own file

Change-Id: Ifbe6580bb42a4e29a42b37e521b68b2e6c89a104