[autotests] Test popup open/close animations

Summary:
The new test is similar to testToplevelOpenCloseAnimation. The
main purpose of this test is to verify that the Fading Popups effect
animates all sorts of popups, e.g. popup menus, tooltips, etc.

testAnimateUserActionsPopup is skipped for now because stuff
that animates unmapped clients is broken.

Reviewers: #kwin, davidedmundson

Reviewed By: #kwin, davidedmundson

Subscribers: kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D17992