Add an id to the organization form

This makes it easier and more reliable for test code to find the form

ckan/templates/organization/snippets/organization_form.html

@@ -1,6 +1,6 @@
 {% import 'macros/form.html' as form %}
 
-<form class="dataset-form form-horizontal" method="post" data-module="basic-form">
+<form id="organization-form" class="dataset-form form-horizontal" method="post" data-module="basic-form">
   {% block error_summary %}
     {{ form.errors(error_summary) }}
   {% endblock %}