[Folder View] improve label contrast against challenging backgrounds
Currently the shadow behind Folder View items' labels is very subtle. This leads to poor contrast against wallpapers that are light-colored, visually busy, or both.
This patch attempts to improve the situation by tightening up the shadow so that it looks more like a subtle, tasteful outline.
Folder View items against various wallpapers:
Folder View items against the default wallpaper:
Reviewed By: Plasma, hein
Subscribers: abetts, svenmauch, matheusm, filipf, emateli, mart, plasma-devel
Differential Revision: https://phabricator.kde.org/D16968