Port all plasma workspace to new libkworkspace API
Summary:
ContainmentActions had some old windows code was dropped as that's
clearly unused.
logout and leave actions now enable/disable at runtime, so in future can
respond to config changes when that's added to libkworkspace.
DataEngines and the krunner code should have no visible changes
Test Plan:
Left from the desktop and from krunner
Changed the default action in ksmserver's kcm
Confirmed that changes the default leave action changed
Reviewers: Plasma, broulik
Reviewed By: Plasma, broulik
Subscribers: broulik, plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D21764