Add dedicated exception for basic.return messages.

[lukebakken]

Fixes #1831

This PR adds the PublishReturnException class that includes the originating exchange and routing key for a basic.return message. It should be backwards-compatible in the API.

[bording]

While it's good to add these properties to the exception for inspection, I'd also really like to see exception messages being added that display these property values in the message text. Those messages tend to get logged along with stack traces and provide useful information in logs. Custom properties on an exception are much less likely to make it into a log file.

[lukebakken]

@SzymonPobiega and @Gsantomaggio all set for a re-review, thanks.

[lukebakken]

While it's good to add these properties to the exception for inspection, I'd also really like to see exception messages being added that display these property values in the message text

Feel free to suggest a patch! Or, modify my PR directly @bording ... I think you have write access here 😸

[bording]

Feel free to suggest a patch! Or, modify my PR directly @bording ... I think you have write access here 😸

I pushed up a change to add exception messages. The interesting one is for the return messages because there really isn't any useful information to include for a nack.

[lukebakken]

Thanks everyone!