Improve values.yaml structure

[SvenLehmann]

This PR cleans up the structure of the accepted values.yamls for both the Deployment Helm chart and the cleanup Job chart. The old way of specifying environment under env is still supported.

• Required values, such as brokers or schema registry url, can now defined on the top level
• Kafka Streams config can now be passed as a YAML map instead of a string
• Add '-clean'-suffix to name of cleanup pods