AMQP-332 Fix Multiple Listeners with Id

Previously, if the parent `<listener-container/>` element
was given an Id, and multiple `<listener/>` elements existed
only one listener container bean was defined - the parent
element Id was used for the bean name.

- Use the child element id if present
- Disallow multiple child elements with the same id
- If a single child element has no id, use the parent
- If multiple elements with the same id exist, use the parent id + '#n'.