feat(settings): Add tokens url to user settings _urls

ref: #650 #649

app/settings/serializers/user_settings.py

@@ -48,6 +48,13 @@ class UserSettingsModelSerializer(UserSettingsBaseSerializer):
 
         return {
             '_self': reverse("v2:_api_v2_user_settings-detail", request=self._context['view'].request, kwargs={'pk': item.pk}),
+            'tokens': reverse(
+                "v2:_api_v2_user_settings_token-list",
+                request=self._context['view'].request,
+                kwargs={
+                    'model_id': item.user.pk
+                }
+            )
         }