[effects] Put Window Aperture and eye On Screen in an exclusive category
Summary:
Having these two enabled doesn't make sense. Also, Window Aperture + eye
On Screen looks really weird.
Test Plan:
Opened the Desktop Effects KCM, both the Window Aperture effect and the
eye On Screen effect are in an exclusive category:
Reviewers: KWin, Plasma, VDG, davidedmundson, ngraham
Reviewed By: KWin, Plasma, VDG, davidedmundson, ngraham
Subscribers: ngraham, davidedmundson, kwin
Tags: KWin
Differential Revision: https://phabricator.kde.org/D14456