LiveWire tool issues and improvements
Increase "hit box" for contour points.
Add segment that visually connects the current mouse position with the contour start point with a straight line.
Always close the contour on double click , not just if start point is clicked.
Test Plan: manual
Reviewers: O1 MITK Reviewer Group I, floca, O3 MITK Reviewer Group II
Reviewed By: O1 MITK Reviewer Group I, floca, O3 MITK Reviewer Group II
Subscribers: kahl, floca
Maniphest Tasks: T28607
Differential Revision: https://phabricator.mitk.org/D522