docs: problematic RabbitMQ queue states

The main intention for adding this piece of documentation is to help users resolve the MessageNacked errors which can seem a bit cryptic at first. It also includes recommended alerts, of which the alert RabbitMQQuorumQueuesAccumulatingMessages is necessary to prevent MessageNacked errors in time. There were also some rearrangements made inside the RabbitMQ troubleshooting guide and missing information for fixing broken queues was added.