Invalid AMQP message with missing application-data section

[ansd]

The AMQP spec writes clearly and unambiguously that each AMQP message must have at least once application-data (body) section:

The body section may denote an empty body though.
However, it's not allowed to completely omit the body section.
This library however sends AMQP messages completely omitting the body section, which is a bug.

Reproduction:

let message = new Message(Properties = new Properties())

More context in rabbitmq/rabbitmq-server#15048 and rabbitmq/rabbitmq-server#14967

[ansd]

One solution could be that this library could default to a data section with a binary of length 0, if the application constructs a message without a body. What do you think? This should be backwards compatible for Azure Service Bus.