Sort services and orgs in presentation layer

The model layer shouldn’t need to be concerned with sorting. For
services this means we can make a `SerialisedModelCollection` rather
than writing a manual loop.

app/models/user.py

@@ -293,9 +293,9 @@ class User(JSONModel, UserMixin):
     @property
     def services(self):
         from app.models.service import Service
-        return sorted(
+        return [
             Service(service) for service in self.orgs_and_services['services']
-        )
+        ]
 
     @property
     def services_with_organisation(self):

app/templates/views/choose-account.html

@@ -19,7 +19,7 @@
   {% else %}
     <ul>
   {% endif %}
-  {% for org in organisations %}
+  {% for org in organisations|sort %}
     <li class="browse-list-item">
       <a href="{{ url_for('.organisation_dashboard', org_id=org.id) }}" class="govuk-link govuk-link--no-visited-state">{{ org.name }}</a>
       <p class="browse-list-hint">
@@ -28,7 +28,7 @@
       </p>
     </li>
   {% endfor %}
-  {% for service in services %}
+  {% for service in services|sort %}
     <li class="browse-list-item">
       <a href="{{ url_for('.service_dashboard', service_id=service.id) }}" class="govuk-link govuk-link--no-visited-state">{{ service.name }}</a>
     </li>