Enable selecting all installed color schemes in Cuttlefish
Summary:
By using KColorSchemeManager we can enable viewing icons with all installed
color schemes. Also all the color setting everywhere can be dropped.
Test Plan:
Reviewers: Plasma, ngraham
Reviewed By: ngraham
Subscribers: ngraham, plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D25273