Remove "move zoomed area" shortcuts by default

Summary: This is a follow-up for D11377, as requested by @graesslin. The patch removes the default shortcuts for the Move zoomed area actions.

Test Plan:
Deployed KWin with patch, killed and restarted KWin, created and logged into new user account, then zoomed in:

• Meta+Ctrl+Arrows do not move the zoomed view
• The actions are still visible (without shortcuts) in System Settings → Shortcuts → Global Shortcuts → KWin
• You can still set custom shortcuts for the actions, and they work

Reviewers: KWin, graesslin

Reviewed By: KWin, graesslin

Subscribers: graesslin, kwin

Tags: KWin

Differential Revision: https://phabricator.kde.org/D11526