Since exchange and rk are already passed in the MMP of Spring-AMQP2.3.4, would you consider refactoring the sender's code

[zysaaa]

Hi! I have some thoughts about the sender module.

Since the MessagePostProcessor of SpringAMQP-2.3.4 has passed the exchange and routingkey, would you consider refactoring the sender's code. (spring-projects/spring-amqp#1267)

With this new feature, a custom MPP can implement the sender's logic without having to use AOP to intercept a large number of methods in AmqpTemplate.