[autotests] Fix maximize test
Summary:
testMaximizedPassedToDeco was failing because it didn't handle async
maximization.
testBorderlessMaximizedWindow was failing because setNoBorder can modify
geometry, so we end up with a wrong restore geometry.
Reviewers: KWin, davidedmundson
Reviewed By: KWin, davidedmundson
Subscribers: davidedmundson, kwin
Tags: KWin
Differential Revision: https://phabricator.kde.org/D16755