[KMessageWidget] Draw it with QPainter instead of using stylesheet
Summary:
While being a prepatory step to KMessageWidget respecting the current color
scheme via KStyle this also simplifies this widget by a huge amount. This
includes removing the nested content Frame and the indirection via a QPixmap
for the animations.
Test Plan:
kmessagewidgettest works as before
Before:
After:
Reviewers: Frameworks, ngraham, cfeck
Reviewed By: ngraham, cfeck
Subscribers: apol, cfeck, dhaumann, ngraham, kde-frameworks-devel
Tags: Frameworks
Differential Revision: https://phabricator.kde.org/D27035