(maybe) Implement target on a per-message basis.

[Gsantomaggio]

Is your feature request related to a problem? Please describe.

In the Java client, the target can be defined on a per-message basis.

Describe the solution you'd like

Like:

// publish to an exchange with a routing key
Message message1 = publisher.message()
    .toAddress().exchange("foo").key("bar")
    .message();

// publish to an exchange without a routing key
Message message2 = publisher.message()
    .toAddress().exchange("foo")
    .message();

// publish to a queue
Message message3 = publisher.message()
    .toAddress().queue("my-queue")
    .message();

Describe alternatives you've considered

No response

Additional context

No response

[Gsantomaggio]

closed via #76