INT-2791 temp-channel-transacted for AMQP Channel

JIRA: https://jira.spring.io/browse/INT-2791

* Add `template-channel-transacted` attribute for the `<amqp:channel>`s to separate configuration for
container and RabbitTemplate
* Make container's `channelTransacted` as `false` by default
* Upgrade to `S-AMQP-1.4.0`
* Add `AmqpHeaders.PUBLISH_CONFIRM_NACK_CAUSE` according to the new `RabbitTemplate.ConfirmCallback#confirm` signature

Conflicts:
	src/reference/docbook/whats-new.xml

Conflicts:
	src/reference/docbook/whats-new.xml

INT-2791: Polishing

Upgrade to S-AMQP-2.0

Fix for mock publisher confirm/return tests, since `channel` is now physically closed, if the `ConnectionFactory` isn't `CachingConnectionFactory`
INT-3499 AMQP Confirms/Returns Polishing

JIRA: https://jira.spring.io/browse/INT-3499

- Suppress expected exception from log in test case
- Suppress (log) 'null' payload error when no correlation data
- Enforce a specific amqp template reference in the parser when using confirms/returns
- Change tests to use a dedicated template for confirms/returns