Summary:
This change adds support for marking the OnScreenMessage as it should
skip close animation. The screenshot effect is adjusted to use the
on screen message instead of the custom effect frame.
Test Plan: Message window is not captured when taking screenshot
Reviewers: #kwin, #plasma_on_wayland
Subscribers: plasma-devel, kwin
Tags: #plasma_on_wayland, #kwin
Differential Revision: https://phabricator.kde.org/D4091
d38bce776f