[kcmkwin] Use new icons for virtual desktops, touch screen, and screen edges KCMs
Summary: New icons were added in D18483 and D18490, so this is 5.16 only.
Test Plan:
Reviewers: VDG, Plasma, ndavis
Reviewed By: VDG, ndavis
Subscribers: kwin
Tags: KWin
Differential Revision: https://phabricator.kde.org/D18492