tests: Add tests for grab interaction with gestures
tests: Add tests for grab interaction with gestures

The behavior of gestures that are kept outside/inside a grab is tested,
to ensure the former are cancelled and the latter remain unchanged.

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