Enhance AMQP Mirror support with dual mirror

at the current Mirror version, we can only mirror into a single direction.

With this enhancement the two (or more brokers) would be connected to each other, each one having its own ID, and each one would send updates to the other broker.

The outcome is that if you just transferred producers and consumers from one broker into the other, the fallback would be automatic and simple. No need to disable and enable mirror options.