fix(#1707): accept citrus_kafka_messageKey and rename custom IT sample Map citrus_kafka_messageKey to KafkaMessageByKeySelector and align the KafkaEndpointJavaIT custom example with KafkaMessageByTopicSelector.
fix(#1707): accept citrus_kafka_messageKey and rename custom IT sample Map citrus_kafka_messageKey to KafkaMessageByKeySelector and align the KafkaEndpointJavaIT custom example with KafkaMessageByTopicSelector.