IULRDC-184 RDC: minor site fixes

[rdlebeau]

• collections and subcollections no longer display the number of items in the collection twice, just once
• the “Status" grid heading is now capitalized on the "Review Submissions" Dashboard page
• Admin Set appears only once in the Collection Type filtering dropdown on the Collections pages on the Dashboard. Previously it appeared twice, as “Admin Set” and as “Hyrax::AdministrativeSet”