Duplicate items in "The list of groups media item belongs to"

Problem/Motivation

Seeing duplicate entries for "The list of groups media item belongs to" on media items.
Duplicate items

Steps to reproduce

Create a media item in a group, visit media item. Seems to happen when a media item is associated with two different users, nodes, etc. Essentially, multiple associations are being reported for the same item.

Proposed resolution

Add the label as a key to the array to filter out duplicates. I also changed the weight of the item in the alter to bring it up above the actions buttons.