Add new platform admin page

Added a new platform admin page, at '/plaform-admin-new' which shows
different data. This no longer offers the option to filter by test-key,
only by date, and also gives a more detailed break-down of the
notifications and failures sent with a normal / research key.

The existing platform admin stats page ('/platform-admin') has not been
deleted yet so that both pages can be compared.

app/templates/components/big-number.html

@@ -55,3 +55,19 @@
     {% endif %}
   </div>
 {% endmacro %}
+
+
+{% macro big_number_simple(number, label) %}
+  <div class="big-number-dark bottom-gutter-2-3">
+    <div class="big-number-number">
+      {% if number is number %}
+        {{ "{:,}".format(number) }}
+      {% else %}
+        {{ number }}
+      {% endif %}
+    </div>
+    {% if label %}
+      <span class="big-number-label">{{ label }}</span>
+    {% endif %}
+  </div>
+{% endmacro %}