Permissions for Finding Aid

Provide a way to restrict a work type to only a group of people.
What happens if the `@permissions[work_type.to_s]` returns nil?

`is_user_part_of_rbsc_finding_aid_group?` is confusing in name. It takes a group_id and checks the user's groups to see if that group id is included. What name this `is_user_part_of_rbsc_finding_aid_group?`