METRON-1572 Enhance KAFKA_PUT function

[nickwallen]

Note: This PR is built on the shoulders of #1023. To review the change specific to this PR, review the changes made in the second commit or wait until #1023 is merged.

Changes

• Enhances the KAFKA_PUT function to accept either a list of strings or a string. This makes it simpler to send either 1 message or a bunch of messages.

• KAFKA_PUT should queue up all messages to be sent before waiting on a response. This improves response time when sending a large number of messages.

Testing

1. Launch the development environment.

2. Launch the REPL in the development environment.

3. Tail some messages from Kafka

   msgs := KAFKA_TAIL("bro", 10)
   

4. Put those message back onto a new topic.

   KAFKA_PUT("new-topic", msgs)
   

5. Validate that the 10 messages landed on the new topic.

Pull Request Checklist

• Is there a JIRA ticket associated with this PR? If not one needs to be created at Metron Jira.
• Does your PR title start with METRON-XXXX where XXXX is the JIRA number you are trying to resolve? Pay particular attention to the hyphen "-" character.
• Has your PR been rebased against the latest commit within the target branch (typically master)?
• Have you included steps to reproduce the behavior or problem that is being changed or addressed?
• Have you included steps or a guide to how the change may be verified and tested manually?
• Have you ensured that the full suite of tests and checks have been executed in the root metron folder via:
• Have you written or updated unit tests and or integration tests to verify your changes?
• If adding new dependencies to the code, are these dependencies licensed in a way that is compatible for inclusion under ASF 2.0?
• Have you verified the basic functionality of the build by building and running locally with Vagrant full-dev environment or the equivalent?

[james-sirota]

+1, executed test instructions, got correct output