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.

tests/app/main/views/test_accept_invite.py

@@ -148,6 +148,8 @@ def test_accepting_invite_removes_invite_from_session(
     mock_get_service_statistics,
     mock_get_template_folders,
     mock_get_usage,
+    mock_get_billable_units,
+    mock_get_free_sms_fragment_limit,
     mock_get_inbound_sms_summary,
     fake_uuid,
     user,
@@ -471,6 +473,7 @@ def test_new_invited_user_verifies_and_added_to_service(
     mock_get_users_by_service,
     mock_get_service_statistics,
     mock_get_usage,
+    mock_get_free_sms_fragment_limit,
     mock_create_event,
     mocker,
 ):