Merge VisibleGroups into ListGroups

ListGroups was the only user of VisibleGroups. Instead of forwarding
calls from ListGroups to VisibleGroups move the code into ListGroups
and get rid of VisibleGroups.

Change-Id: Ie5dd6035487448486036a94f11f1e9237cc19012
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>
4 files changed