Processes a batch of OTT messages for delivery via configured channels (e.g., WhatsApp).The OTTProcessingResult object represents the outcome of processing an individual OTT message within a batch request. It contains the recipient's phone number, a unique message identifier if the message was successfully queued, a status indicator ("queued" or "error"), and an optional error message describing why the message failed. This structure allows clients to correlate each input message with its delivery status and diagnose issues such as invalid templates, routing failures, or malformed data. A response may contain multiple OTTProcessingResult entries, one for each attempted delivery, enabling granular feedback and partial success handling.