Refactor gtk_widget_set_device_enabled_internal
Refactor gtk_widget_set_device_enabled_internal

Instead of constructing a single list of all windows associated
to a widget, just iterate the children lists recursively, avoiding
allocations.

grubersjoe/adwaita,alexlarsson/gtk,grubersjoe/adwaita,grubersjoe/adwaita,alexlarsson/gtk,alexlarsson/gtk,alexlarsson/gtk,alexlarsson/gtk,grubersjoe/adwaita,grubersjoe/adwaita,alexlarsson/gtk,alexlarsson/gtk,grubersjoe/adwaita,grubersjoe/adwaita,grubersjoe/adwaita,alexlarsson/gtk