Rework concentration via VFA calculation.
Summary:
Make baseline averaging available for all conversion methods for 4D images.
Rename Variable Flip Angle Parameters box.
Minor correction, remove unnecessary MITK_INFO lines.
Adapt concentration conversion unit test to changes in VFA method.
Test Plan: Manually
Reviewers: floca, O3 MITK Reviewer Group II
Reviewed By: floca, O3 MITK Reviewer Group II
Differential Revision: https://phabricator.mitk.org/D864