Avoid invalid geometry of internal clients through plasma surface interface
Summary:
Internal KWin windows might be not in sync with their PlasmaShellSurface.
This could be a problem in general, but for now atleast guard against
invalid setPosition requests.
BUG: 386304
Test Plan: Manually
Reviewers: KWin, davidedmundson
Subscribers: davidedmundson, ngraham, graesslin, kwin
Tags: KWin
Maniphest Tasks: T8771
Differential Revision: https://phabricator.kde.org/D13084