[Epic] General CI/CD improvements

We have several issues and ideas regarding CI/CD changes and improvements. These should be done together with #555, to have consistent pipeline update for this.

The invidual issues need to be done before this one is closed.

• Validating Kubernetes configuration files #559 (closed)
• Docker image for CI/CD #558 (closed)
• Conformance checks for MRs #557 (closed)
• etcd docker image #542 (closed)
• Kafka integration tests #417 (wont be done for now due to time restrictions)
• General updates to CI/CD templates, grammar (Housekeeping)