[Folder View] make file context menu consistent with Dolphin's

Summary:
BUG: 401652
FIXED-IN: 5.15.0

Test Plan:
Before:

After:

It matches Dolphin:

Reviewers: Plasma, hein, VDG, ndavis

Reviewed By: Plasma, hein, VDG, ndavis

Subscribers: ndavis, mart, janpr, plasma-devel

Tags: Plasma

Differential Revision: https://phabricator.kde.org/D17393