[Plasma Components 3] Fix RTL in some widgets.

Summary: Some widgets are missed up in RTL mode, this should fix it.

Reviewers: Plasma, Frameworks, mart

Reviewed By: Plasma, mart

Subscribers: mart, broulik, davidedmundson, plasma-devel

Tags: Plasma, Frameworks

Differential Revision: https://phabricator.kde.org/D7715