Embrace X-KDE-Wayland-Interfaces

Summary:
Requests several KWin-specific interfaces to be used on KRunner and
Plasma Shell.

Test Plan: See D22571

Reviewers: #plasma, #kwin, davidedmundson

Reviewed By: #plasma, #kwin, davidedmundson

Subscribers: davidedmundson, zzag, mvourlakos, plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D22589