[Segmentation Documentation] Updated images

Summary: Updated outdated images in the segmentation plugin documentation

Test Plan: open the documentation (MITK User Manual >> MITK Plugin Manuals >> List of General Purpose Plugins >> The Segmentation View OR Open MITK workbench >> open the segmentation plugin >> press F1). There you should see the updated images

Reviewers: kalali, O1 MITK Reviewer Group I, O3 MITK Reviewer Group II

Reviewed By: kalali, O1 MITK Reviewer Group I, O3 MITK Reviewer Group II

Maniphest Tasks: T29136

Differential Revision: https://phabricator.mitk.org/D630