[kcmkwin/kwindecoration] Refine drag-and-drop button UI
Summary:
- Reduce the fake titlebar's height so it matches the real titlebar a bit better
- Reduce background opacity while dropping button to diminish visual noise
- Increase label size
- Re-word label for greater clarity
- Remove redundant icon (the text is enough)
BUG: 407109
FIXED-IN: 5.16.0
Test Plan: {F6804068, size=full}
Reviewers: #vdg, #kwin, GB_2, davidedmundson
Reviewed By: #vdg, #kwin, GB_2, davidedmundson
Subscribers: GB_2, abetts, kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D20968
48cacae8cf