wayland: xdg-shell: add support for configure_bounds

xdg-toplevel's configure_bounds event report the maximum size the compositor would like to handle for presenting the window the best way possible, which prevents creating a bigger window than the desktop screen itself.

Tested against kwin-git in embedded mode to check different desktop sizes.

See wayland-protocols¹ merge request, the protocol is due to be implemented in mutter and GTK but is currently only merged² in kwin.

I haven't checked in details if the bump of xdg-wm-base could be harmful, but a quick search on wayland.app didn't bring anything up.

Closes #26730 (closed)

1. https://gitlab.freedesktop.org/wayland/wayland-protocols/-/merge_requests/41 ↩

2. https://invent.kde.org/plasma/kwin/-/merge_requests/1808 ↩