inspector: Add menu models to the tree
inspector: Add menu models to the tree

Add both the appmenu and the menubar models as children of the
application, if they exist.

alexlarsson/gtk,jadahl/gtk,chergert/gtk,Lyude/gtk-,jadahl/gtk,davidgumberg/gtk,Lyude/gtk-,Lyude/gtk-,ahodesuka/gtk,grubersjoe/adwaita,jigpu/gtk,davidgumberg/gtk,alexlarsson/gtk,Lyude/gtk-,grubersjoe/adwaita,Adamovskiy/gtk,jadahl/gtk,Lyude/gtk-,jigpu/gtk,davidgumberg/gtk,ahodesuka/gtk,davidgumberg/gtk,chergert/gtk,ahodesuka/gtk,davidgumberg/gtk,Adamovskiy/gtk,jadahl/gtk,chergert/gtk,grubersjoe/adwaita,alexlarsson/gtk,Adamovskiy/gtk,chergert/gtk,jadahl/gtk,jigpu/gtk,Adamovskiy/gtk,jigpu/gtk,davidgumberg/gtk,Adamovskiy/gtk,alexlarsson/gtk,jigpu/gtk,Lyude/gtk-,alexlarsson/gtk,jadahl/gtk,chergert/gtk,Adamovskiy/gtk,davidgumberg/gtk,alexlarsson/gtk,grubersjoe/adwaita,alexlarsson/gtk,davidgumberg/gtk,jigpu/gtk,chergert/gtk,ahodesuka/gtk,Adamovskiy/gtk,chergert/gtk,ahodesuka/gtk,alexlarsson/gtk,Lyude/gtk-,jigpu/gtk,grubersjoe/adwaita,ahodesuka/gtk,grubersjoe/adwaita,chergert/gtk,jadahl/gtk,grubersjoe/adwaita,jadahl/gtk,ahodesuka/gtk,Adamovskiy/gtk,jigpu/gtk,Lyude/gtk-,grubersjoe/adwaita,ahodesuka/gtk