Block on message disposition when rcv-settle-mode is second

[vcabbage]

amqp/client.go

Lines 1382 to 1389 in ee6eb7e

	// TODO:
	// When rcv-settle-mode == second, don't consider the transfer complete
	// until caller accepts/reject/etc and a confirm from sender.
	//
	// At first glance, this appears to be at odds with batching. A batch can't
	// be built up if the caller is blocked on confirmation. However, while receives
	// must happen synchronously, confirmations do not. While the use is probably
	// limited it may be worth exploring.