change user_name still used as login and add display_name for dashboard view instead of username on login

backend/apps/jobs/tests.py

@@ -15,8 +15,8 @@ from django.core.management import call_command
 class BootstrapAdminTests(TestCase):
     def test_creates_break_glass_superuser_without_demo_data(self):
         call_command("bootstrap_admin")
-        user = User.objects.get(user_login="admin")
-        self.assertEqual(user.user_name, "admin")
+        user = User.objects.get(user_name="admin")
+        self.assertEqual(user.display_name, "admin")
         self.assertEqual(user.status, User.STATUS_SUPERUSER)
         self.assertTrue(user.is_superuser)
         self.assertTrue(user.check_password("Pr04dm1n"))
@@ -34,8 +34,8 @@ class BootstrapAdminTests(TestCase):
     )
     def test_creates_gm_when_configured(self):
         call_command("bootstrap_admin")
-        staff = User.objects.get(user_login="staff")
-        self.assertEqual(staff.user_name, "staff")
+        staff = User.objects.get(user_name="staff")
+        self.assertEqual(staff.display_name, "staff")
         self.assertEqual(staff.status, User.STATUS_GM)
         self.assertFalse(staff.is_superuser)
         self.assertTrue(staff.check_password("St4ff!"))