Support - Consumer.NegativeAcknowledge

[NegativeAcknowledge](http://pulsar.apache.org/docs/en/concepts-messaging/#negative-acknowledgement) provides a nice way to shape error handling when messages cannot be processed and you want to do so at a later time with a given timeout:

*Prefer negative acknowledgements over acknowledgement timeout. Negative acknowledgement controls the re-delivery of individual messages with more precision, and avoids invalid redeliveries when the message processing time exceeds the acknowledgement timeout.*

Start with the Consumer API and the Apache Pulsar NegativeAcknowledge documentation linked in the issue. Determine the intended timeout and redelivery behavior, then verify that the requested Consumer support matches those semantics; no source files or tests are named in the issue.

Written by the indexing model from the issue text.