Remove redundant / unused QmitkSliceBasedInterpolatorWidget
Summary:
Remove unused QmitkSliceBasedInterpolatorWidget class
The class was used by the MultilabelSegmentationView,
which has been removed.
Test Plan: check CI builds
Reviewers: s349i, O1 MITK Reviewer Group I, kislinsk
Reviewed By: O1 MITK Reviewer Group I, kislinsk
Subscribers: kalali, s349i
Maniphest Tasks: T28669
Differential Revision: https://phabricator.mitk.org/D699