Don't display duplicated security groups

As reported by users, we end up displaying duplicate security groups
on multi nic vms using neutron. Let's not do that.

Also add security group listing to the v3 client to make it
consistent.

Change-Id: I0a983aac08aaeacf3c2aef5aae49f64265fe78c5
Closes-Bug: #1331307
Merge "Don't display duplicated security groups"