Make use of Kafka Key for Audit service and Kafka listener
* When message is sent by audit service, key will be the CBA name
* When sent by kafka listener (self-service api), key is the same as the request message key consumed. If not specified, a random UUID
* MessageProducer interface refactoring :
* add 'key' parameter to specify a key
* add default value null to paramater 'headers' to remove some unnecessary method
Issue-ID: CCSDK-2628
Signed-off-by: Julien Fontaine <julien.fontaine@bell.ca>
Change-Id: I68580151184c87104c07037f379276dd8c8c71c7