Reinstate retrieval of the package_id from the connection context in child-resources, the problem was that, when we required a connection context in create_form_page_instance, we did with no information whatsoever, which was then retrieved by e.g. ns_conn, sometimes wrongly (e.g. when one is running under the test package)
child-resources has already a package_id, getting it from the connection context makes the includelet susceptible to e.g. package initializations from the outside (see e.g. xowiki link_tests automated test)