Big overhaul

[berndruecker]

• Update to Camunda 8.x
• Switch Spring Cloud Streams to normal KafkaListener (more robust and better compatibility with other Spring things)
• Remove unmaintained parts of the code, this mostly means:
  • NodeJS examples
  • Camunda 7
  • K8S deployment files

• Add Github Action to build artifacts and deploy on DockerHub
• Update Choreography Example (use latest Optimize with Identity and Event Ingestion)

[berndruecker]

These are the steps I did locally: build.txt