A verified message.received webhook delivery, from Unicom360.Webhook.construct_event/4.
event-"message.received".delivery_id- theX-Unicom360-Deliveryheader (nilwhen absent). Deliveries are retried, so drop repeats by it.created_at- an ISO 8601 string, as received.data- aUnicom360.Webhook.InboundMessage.raw,extra- the JSON object, and the members this version does not model.