[aurorae] Add support for shaded windows
Summary:
Aurorae did not render correctly. This change addresses the problem for
both maximized and restored windows.
BUG: 373319
FIXED-IN: 5.10.4
Test Plan: shaded windows with Plastik and SVG based theme
Subscribers: plasma-devel, kwin
Tags: KWin
Differential Revision: https://phabricator.kde.org/D6719