[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