feat: add Quarkus examples app as GraalVM native image

[hartmut-co-uk]

I want to add a quarkus app of the 'word count' topology to have a GraalVM native app example part of the project.

This will allow to test & experiment with rebalancing behaviour for low-latency requirements.

The docker-compose stack should have complete 3-node clusters of Kafka & Cassandra/ScyllaDB.

[hartmut-co-uk]

closed with #8