@elliotcm supporting pages don't get scoped to their policy in the admin interface in quite the same way as corporate information pages do with their organisation - we need to each CIP to be explicitly scoped to it's org, otherwise there is no way to distinguish them from one another as many share the same "slug".

Having said that, this routing helper is relying on a helper method defined on `Admin::CorporateInformationPagesController`, which is bad as it means it cannot be used anywhere else outside of the context of that controller or its views, for example `Whitehall.url_maker`. I would argue that this helper should not exist at all, and that we should use the pre-existing `admin_organisation_corporate_information_pages_path` helper where required.