Link to Issue

Closes: #11757

Description of Changes

• Adds migration to backfill nomination groups on existing communities with namespaces
• Adds policy logic to create group after namespace has been created

Test Plan

• Find an existing community w/ namespace- verify it has a "Community Nominated" Group
• Create a new community and create a namespace for it– verify it has a "Community Nominated" group

Deployment Plan

N/A

Other Considerations

N/A