Add an attribute for a group to the user profile

[georgiamoon]

Based on a collaboration with open journals, we need a way to reference all users that are a part of this collective review effort.

[georgiamoon]

@dasaderi's mockup of what this could look like

[murkatr]

Update: We are no longer labeling OASPA Initiative reviewers - only COVID reviews.

[georgiamoon]

@murkatr re-opening — I think we want to keep this feature open but for later, this just isn't going to be a priority right now.

[murkatr]

Linking this to the new "Community Features" milestone for the "New Merge" project under the "PREreview/prereview" repo.