A retail company is building an order-processing system. Front-end web servers must submit order messages that back-end worker services process asynchronously. Individual messages are small (under 20 KB), but the system must guarantee first-in-first-out (FIFO) ordering, detect and remove duplicate submissions, and support transactional grouping of related messages. The team wants a fully managed Azure messaging service and prefers to minimize custom code. Which service should you recommend?