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/main/views/dashboard.py

@@ -299,7 +299,14 @@ def get_dashboard_partials(service_id):
         )
         for key, value in dashboard_totals[0].items()
     )
-
+    free_sms_allowance = billing_api_client.get_free_sms_fragment_limit_for_year(
+        current_service.id,
+        get_current_financial_year(),
+    )
+    yearly_usage = billing_api_client.get_service_usage(
+        service_id,
+        get_current_financial_year(),
+    )
     return {
         'upcoming': render_template(
             'views/dashboard/_upcoming.html',
@@ -332,7 +339,12 @@ def get_dashboard_partials(service_id):
             'views/dashboard/_jobs.html',
             jobs=immediate_jobs
         ),
-        'has_jobs': bool(immediate_jobs)
+        'has_jobs': bool(immediate_jobs),
+        'usage': render_template(
+            'views/dashboard/_usage.html',
+            column_width=column_width,
+            **calculate_usage(yearly_usage, free_sms_allowance),
+        ),
     }