D6118: refine layouts for items to be more aligned

[Marco Martin]

mart added a reviewer: abetts.

REPOSITORY
  R124 System Settings

REVISION DETAIL
  https://phabricator.kde.org/D6118

To: mart, #plasma, #vdg, abetts
Cc: plasma-devel, ZrenBot, spstarr, progwolff, lesliezhai, ali-mohamed, 
jensreuterberg, abetts, sebas, apol, mart, lukas