Let users delete a contact list

Follows our standard pattern of confirming with a red banner for actions
that are destructive.

app/templates/views/uploads/contact-list/contact-list.html

@@ -45,4 +45,14 @@
     </p>
   {% endif %}
 
+  {% if not confirm_delete_banner %}
+    <div class="js-stick-at-bottom-when-scrolling">
+      <div class="page-footer">
+        <span class="page-footer-delete-link page-footer-delete-link-without-button">
+          <a class="govuk-link govuk-link--destructive" href="{{ url_for('main.delete_contact_list', service_id=current_service.id, contact_list_id=contact_list.id) }}">Delete this contact list</a>
+        </span>
+      </div>
+    </div>
+  {% endif %}
+
 {% endblock %}