Prevent "Two clicks renaming" if the selected file/folder is not movable

Summary:
Two clicks renaming doesn't check if the user is actually allowed to rename a file/folder. With this patch, this get fixed.
Depends on D7647

Reviewers: rkflx, Dolphin, ngraham

Reviewed By: Dolphin, ngraham

Subscribers: elvisangelaccio, ngraham, Dolphin

Differential Revision: https://phabricator.kde.org/D8740