nnUNet: Migrating to QmitkSingleNodeSelectionWidget
Summary:
- Migrating to QmitkSingleNodeSelectionWidget for selecting other modalities
- Shift temp directory creation from mitk::nnUNetTool constructor to DoUpdatePreview to increase workbench response time
Test Plan: Segmentation 3D checklist for nnUNet.
Reviewers: floca, kislinsk, O1 MITK Reviewer Group I
Reviewed By: kislinsk, O1 MITK Reviewer Group I
Maniphest Tasks: T29508
Differential Revision: https://phabricator.mitk.org/D788