Disable modifier window actions if global shortcuts are disabled
Summary:
Same is done on X11 (see Client::updateMouseGrab), so we should have this
on Wayland as well.
Also adding the pointer confinement restriction for modifier + wheel.
Test Plan: Run new and adjusted testcases with and without the change
Subscribers: kwin
Tags: KWin
Differential Revision: https://phabricator.kde.org/D16025