Expose additional lifecycle (consumer/producer) callbacks

[olegz]

While working on spring-cloud/spring-cloud-stream#1055 I've realized that at the moment si-kafka (KafkaMessageDrivenChannelAdapter) doesn't expose the appropriate callbacks to perform pause/resume etc.
Could you please add it

[artembilan]

This won't be enough here. We need pause()/resume() on the container contract - in Spring Kafka.