Move switch service out of black header

Also following the pattern work that Tim and Stephen have done.

app/templates/admin_template.html

@@ -45,9 +45,6 @@
             <li>
               <a href="{{ url_for('main.user_profile') }}">{{ current_user.name }}</a>
             </li>
-            <li>
-              <a href="{{ url_for('main.choose_service') }}">Switch service</a>
-            </li>
             {% if current_user.has_permissions(admin_override=True) %}
                 <li>
                   <a href="{{ url_for('main.platform_admin') }}">Platform admin</a>