[rmq] Implement Publisher Confirms

[olttwa]

• Enable publisher-confirm mode on client
  • If broker responds with basic.nack for 3 jobs in a row
    • Callback with failed jobs
    • switch to synchronous acks for future jobs
    • switch to async after 5 successful acks
  • Do acks async because latency can be few hundred millis

References

• https://www.rabbitmq.com/tutorials/tutorial-seven-java.html
• https://www.rabbitmq.com/confirms.html#publisher-confirms-latency
• https://www.rabbitmq.com/publishers.html#publisher-confirm-strategies