Changed name generation to use study and series description again.

Summary: Signed-off-by: Ralf Floca <r.floca@dkfz-heidelberg.de>

Test Plan: Review and unit tests

Reviewers: MITK Reviewer Group I, kislinsk

Reviewed By: MITK Reviewer Group I, kislinsk

Maniphest Tasks: T25947

Differential Revision: https://phabricator.mitk.org/D234