Drags outside of the xdg surface don't generate motion events when hovering on top of layer shell

Dragging outside of the surface generally still causes the motion events to be sent to the surface. However, when the finger/pointer goes above a non-background layer-shell surface, the events aren't sent anymore until going back from the layer-shell surface.

This makes things like text selection with touch in Chatty unnecessarily hard.

Happens with both pointer and touch events.