KCM/Kwinoptions: Port title bar and window actions tabs UI and conf to KConfigXT
Summary: Depends on D27463
Reviewers: crossi, bport, ervin, KWin, zzag
Reviewed By: ervin, KWin, zzag
Subscribers: zzag, kwin
Tags: KWin
Differential Revision: https://phabricator.kde.org/D27477