Make the action selector OSD independent of the other OSDs
Summary:
This OSD should handle keyboard input and behave different, so make it work on its own.
In follow up changes, the keyboard handling will be added.
CCBUG: 395804
Reviewers: Plasma, davidedmundson
Subscribers: broulik, davidedmundson, zzag, plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D14143