Disable movie maker view when MxN display is active

Summary: Since the movie maker view is currently not yet compatible with the MxN display (see T29302), it is now disabled when the MxN view is active.

Test Plan: Open the movie maker view. Switch between Std Multi Widget view and Mxn Multi Widget view. Whatever you do, the movie maker should always be disabled when MxN is active.

Reviewers: O3 MITK Reviewer Group II, kislinsk

Reviewed By: O3 MITK Reviewer Group II, kislinsk

Subscribers: kislinsk

Differential Revision: https://phabricator.mitk.org/D808