edit mode action

Summary: needed for the context menu entry

Test Plan: with the p-w- portion the action shows in the context menu

Reviewers: Plasma, VDG, GB_2, ngraham, davidedmundson

Reviewed By: Plasma, VDG, ngraham, davidedmundson

Subscribers: davidedmundson, broulik, GB_2, ngraham, kde-frameworks-devel

Tags: Frameworks

Maniphest Tasks: T10190, T11094, T10402

Differential Revision: https://phabricator.kde.org/D24263