[StandardActionManager] Don't add PendingCutRole when copying

Summary: We shouldn't add `PendingCutRole` (which i.e. greys out items from the EntityTreeView) when we are only copying, not cutting

Test Plan:
Although I've found no PIM applications which use `Copy` action (KMail, KAdressBook and KOrganizer use `Copy To` with a submenu),
I've used this action in KJots (to be able to paste links to various notes / books inside notes, instead of existing `copy_link_address` action), and it works.

Reviewers: dvratil

Reviewed By: dvratil

Subscribers: kde-pim

Tags: #kde_pim

Differential Revision: https://phabricator.kde.org/D29484