[feat] add kafka streaming for event sourcing/cqrs

[Tochemey]

Processed events will be automatically streamed to kafka.

[sdil]

@Tochemey just wondering whether do we want to support other message brokers (eg. NATS, RabbitMQ) in the future? if that's the case, perhaps we can use the same plugin mechanism as the plugin store.

[Tochemey]

@sdil That is a valid point. I need to extract this interface into a more generic way and then we can use the contrib repo to add them.