Implement interactive window selection for Wayland platforms
Summary:
The interactive window selection is implemented in InputRedirection
through a dedicated InputEventFilter. The InputEventFilter so far takes
care of pointer input and keyboard input. In addition it ensures that
keyboard and pointer focus is reset on start and on end.
With this change KillWindow now also works on Wayland, but only for X11
windows, as the Wayland variant is not yet implemented.
Test Plan: Tested in nested setup, auto-tests still needed
Reviewers: KWin, Plasma on Wayland
Subscribers: plasma-devel, kwin
Tags: Plasma on Wayland, KWin
Differential Revision: https://phabricator.kde.org/D3365