Add Reactive Messaging with DataSource and RuleUnit example

Issue Description:

Add Reactive Messaging with DataSource and  RuleUnit test case (or example)

The basic ideas are
KOGITO-6040 "PoC: Reactive Messaging in Rule Units with Kafka"
https://github.com/kiegroup/kogito-examples/pull/933

KOGITO-6039 KOGITO-6040 Vert.X example
https://github.com/kiegroup/kogito-examples/pull/952

Acceptance Criteria:
In the example, DataStream consumes events (e.g. via Kafka topic), so the engine fires reactively.