Improve some strings and UI elements in KWin KCM
Summary:
BUG: 386571
BUG: 386574
BUG: 386576
Implemented some of @abetts' string change and UI suggestions in the above bugs.
Test Plan:
Tested in KDE Neon:
Reviewers: abetts, VDG, KWin, davidedmundson, graesslin, apol
Reviewed By: abetts, VDG, davidedmundson, apol
Subscribers: apol, jriddell, luebking, graesslin, kwin, abetts
Tags: KWin
Differential Revision: https://phabricator.kde.org/D8682