Records the target publish state (PUBLISH or UNPUBLISH) for a batch of products in one context; it does not push anything live by itself. To actually publish or unpublish the products, create a session with create_publish_session, add the same product ids with add_products_to_publish_session, and start it with complete_publish_session. Product ids that do not resolve to an active product in this organization are silently ignored rather than causing a failure.