Enable MITK mouse mode and allow mode switching
Summary: Extend toolbars and actions to switch between mouse modes using the mxnmultiwidget.
Test Plan: - manual
Reviewers: floca, O1 MITK Core
Reviewed By: floca, O1 MITK Core
Subscribers: kalali
Tags: MITK
Maniphest Tasks: T26490
Differential Revision: https://phabricator.mitk.org/D209