Make checkboxes/radiobuttons use Window Background in windows and View Backround in lists
Summary: If the widget has an item view parent, use the View Background color. Otherwise, use Window Background.
Test Plan:
Reviewers: VDG, Breeze, hpereiradacosta, ngraham
Reviewed By: VDG, hpereiradacosta
Subscribers: plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D26639