Big overhaul

[berndruecker]

• [x] Update to Camunda 8.x
• [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:
  • [x] NodeJS examples
  • [x] Camunda 7
  • [x] 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