Summary:
alternative approach: try to resize the winidow to make room for the keyboard.
the new input wayland protocol doesn't have anymore the overlap rectangle (and it would not be going to work with qwidget apps anyways)
in the future will probably be needed anextension to the input protocol v3 which partially gets back this, tough window resizing is needed regardless
what's missing: the resize should be "temporary" and the window should be restored to its previous geometry when the keyboard closes
Test Plan: tested with test QML code
Reviewers: #plasma, #kwin, bshah, graesslin, romangg, davidedmundson
Reviewed By: #plasma, #kwin, romangg, davidedmundson
Subscribers: nicolasfella, mart, kwin, davidedmundson, graesslin
Tags: #kwin
Maniphest Tasks: T9815
Differential Revision: https://phabricator.kde.org/D18818