Fix crash on close of data node details dialog

Summary:

• Use UI file for QmitkNodeDetailsDialog
• Fix crash because of invalidated event recipient

Fixes T30342.

Test Plan: Manual test: Open details dialog for 1 to n data nodes and close the dialog again. Does not crash anymore.

Reviewers: floca, O3 MITK Reviewer Group II

Reviewed By: floca, O3 MITK Reviewer Group II

Maniphest Tasks: T30342

Differential Revision: https://phabricator.mitk.org/D905