Disable threshold tools updating after each entered digit

Summary: Fixes T30271. This disables keyboardTracking for the spinboxes inside the ctkRangeWidget / ctkSliderWidget used in the threshold tools of the Segmentation View.

Test Plan: Use the threshold tools for a segmentation and try entering the threshold values manually in the spinboxes. Now, the preview should only update when the user presses return or the widget loses focus.

Reviewers: O1 MITK Reviewer Group I, kislinsk

Reviewed By: O1 MITK Reviewer Group I, kislinsk

Subscribers: kislinsk

Maniphest Tasks: T30271

Differential Revision: https://phabricator.mitk.org/D960