[image-wallpaper] Port to Kirigami.FormLayout and use twinFormLayouts
Summary:
Porting to Kirigami.FormLayout and using twinFormLayouts in order to ensure alignment with the main layout.
NOTE: Vertical spacing is still clearly wrong, but I could fix that as well if someone could offer a suggestion on how to do it.
Test Plan:
D19932 needed before testing.
Before:
After:
Before:
After:
Everything still worked.
Reviewers: Plasma, ngraham, mart, hein
Reviewed By: Plasma, ngraham, mart, hein
Subscribers: hein, davidre, mart, abetts, plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D19873