Add OIDC fixes, add prefered_username, add application-user claims

test/fixtures/groups.yml

@@ -1,5 +1,13 @@
 # Read about fixtures at https://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html
 
+one:
+  name: Group One
+  description: First test group
+
+two:
+  name: Group Two
+  description: Second test group
+
 admin_group:
   name: Administrators
   description: System administrators with full access