[TASK] Styling for the distribution management

The distribution management looks ugly. Make it usable
and not just a raw list.

Resolves: #57139
Releases: 6.2
Change-Id: I95eb8dca3cd6b3915839736d18ff3d78e746a30a
Reviewed-on: https://review.typo3.org/28615
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn