Add separator and heading to selected clients

ogcp/templates/macros.html

@@ -50,6 +50,7 @@
 {% endmacro %}
 
 {% macro selected_clients() -%}
+<hr><h2>{{_('Selected clients')}}</h2>
 <div id="selected-clients" class="d-flex flex-wrap justify-content-center"></div>
 {% endmacro %}