[wayland] Provide correct input transformation matrix for client-side decorated clients
Summary: Pointer events must be in surface-local coordinates, not window geometry.
Reviewers: KWin, davidedmundson
Reviewed By: KWin, davidedmundson
Subscribers: kwin
Tags: KWin
Maniphest Tasks: T10867
Differential Revision: https://phabricator.kde.org/D24456