Make dock windows resizable but do not allow tiling
This is a proposal to support MR https://invent.kde.org/frameworks/plasma-framework/-/merge_requests/500. The final target is implementing what is requested in https://bugs.kde.org/show_bug.cgi?id=332512.
With this patch kwin should make docked windows in wayland resizable, while preventing the user from tiling. MR https://invent.kde.org/frameworks/plasma-framework/-/merge_requests/500 would then be able to startSystemResize even when the docked window is frameless.
A demo of the final result: https://youtu.be/iSZcLh2yL1E.