Make HB::Channel#queue work the same way exchange convenience methods do
Make sure HB::Queue#bind and #unbind allow for method chaining

Better Bunny compatibility
Gracefully shut down consumer executor pools when channel or the entire connection is closed

This both means we don't leave unused thread pools behind and makes termination of
examples/scripts/apps more predictable for Ruby developers who don't necessarily know
what thread pools are, daemon vs non-daemon threads, how to shut down consumers
manually and so on.
Improve this test