[Cuttlefish] Make it clear that picker mode still works

Summary:
The alternative strings were lost in the quick controls 2 overhaul. Also fixes a
small bug that caused "edit-copy" to be copied to the clipboard everytime when
triggered from the context menu.

Test Plan: Enable plugin in Kate see the changed strings.

Reviewers: #plasma, cblack, ngraham, davidedmundson

Reviewed By: #plasma, davidedmundson

Subscribers: plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D25806