In the old protocol, Kafka Streams used to throw a
`MissingSourceTopicException` when a source topic is missing. In the new
protocol, it doesn’t do that anymore, while only log the status that is
returned from the broker, which contains a status that indicates that a
source topic is missing.
This change:
1. Throws an `MissingSourceTopicException` when source topic is missing
2. Adds unit tests
3. Modifies integration tests to fit both old and new protocols
Reviewers: Lucas Brutschy <lbrutschy@confluent.io>
