Port the "Switch Desktop" containment action to libtaskmanager

Summary:
This:

• Makes it work on Wayland. Depends on D13745.
• Cleans up includes and linkage.
• Fixes some pre-existing bugs like cached actions not updating to changed desktop names.

Reviewers: mart, davidedmundson

Reviewed By: davidedmundson

Subscribers: zzag, broulik, plasma-devel

Tags: Plasma

Maniphest Tasks: T4457

Differential Revision: https://phabricator.kde.org/D15599