Add support to carry CloudEvent's source attribute along with the type #10
Description
Would be great to carry the CloudEvent source attribute along with the type so that event consumers can use the information if needed.
Currently, the CloudEventIngestor maps a CloudEvent to an IntegrationEvent based on the type attribute and instantiates the event based on its data payload only, which makes perfect sense. However, if the event payload does not include anything specific about the source, then the IntegrationEvent consumer has no way to retrieve the information (as it's lost in the enveloppe that was just removed).
It'd be great to carry that info in the IntegrationEvent along with the payload.