Changes to List registrations

removed the optional property items/items/submitted_by_github_login from the response with the 200 status

added the optional property items/items/submitted_by_github_user_id to the response with the 200 status

removed the optional property items/items/contact_email from the response with the 200 status

added the optional property items/items/contact_email to the response with the 200 status