Put usage summary back on the dashboard

This reverts 1b1839ad30, which removed
the usage from the dashboard because it was causing performance
problems:

> **The yearly usage section on the dashboard page takes too log as a
> result services with large yearly stats are timing out.**
>
> As a short term fix we have taken the yearly stats off the dashboard.
>
> There is a plan to create permanent statistic tables to warehouse the
> data.

The long term fix (the fact tables) is now in place, so it should be OK
to bring this back.

This is part of a wider piece of work to refresh the dashboard page now
that jobs are moving to their own page.

app/templates/views/dashboard/dashboard.html

@@ -43,6 +43,15 @@
       ) }}
     {% endif %}
 
+    {% if current_user.has_permissions('manage_service') %}
+      <h2 class='heading-medium'>This year</h2>
+      {{ ajax_block(partials, updates_url, 'usage') }}
+      {{ show_more(
+        url_for(".usage", service_id=current_service['id']),
+        'See usage'
+      ) }}
+    {% endif %}
+
   </div>
 
 {% endblock %}