[Task manager] Use consistent menu items for "pin/unpin" actions
Summary:
Make the pinning-relatedmenu items consistent by showing separate Pin and Unpin menu
items when not using activities. When using activities, it's unavoidable, so we still
show a more complicated UI there with checkboxes for the per-activity pinning options.
BUG: 395615
FIXED-IN: 5.17.0
Test Plan:
Right-click on pinned launchers, open unpinned tasks, and open pinned tasks - see that all have the correct menu items
Do it again with mode than one Activity and see that all is still well
Reviewed By: Plasma, hein
Subscribers: plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D21856