8095:Association editor refuses dropped persons
Create prefilled PersonRef when drop of a Person on Association EmbeddedTab (same as ChildTab)
And drag support to EditPersonRef when person is set
Add person drag support from EditChildRef (always possible as child are
always set)
Allow to drag a person from EditPerson (if not a unsaved person)
Add drag support to parents in EditFamily (when set) and move drop capability if parent already set
Add Support for dragging from the add/choose selector of Place/Source/Media/Note-Entry
Add Person drag support from RelationshipView

Signed-off-by: Bastien Jacquet <bastien.jacquet_dev@m4x.org>
Allow for dragging a family from EditFamily
EditPerson new person calls create_id() to have a handler in clipboard (as in EditFamily)
Add Family drag support from RelationshipView
Allow to drag a person by dragging the "Father/Mother/Spouse" label or around Add/edt/share buttons

Signed-off-by: Bastien Jacquet <bastien.jacquet_dev@m4x.org>
8149: Error on opening twice an object from clipboard because of missing import