fix wrong popups Z-order after applying "Show Desktop" effect
Normal Z-order
Wrong Z-order after "Show desktop" shortcut
Keyboard layout OSD is hidden by the menu:
For some reason, layers are changed during the Show Desktop effect applied, so
we will have AboveLayer for our popups and Desktop, and NotificationLayer
for Dock which hides us. After cancelling the effect, it returns back to normal.
Also, OSD and critical notifications were always hidden by our popups.
This patch solves both the issues.
Usual notifications will still be hidden, but hopefully it's not a big
issue.
Edited by Andrey Butirsky