Alarms: Kafka without zookeeper #3441

Recent versions of Kafka no longer use zookeeper.

I've tried running the alarm server and the alarm GUI with kafka_2.13-4.0.0, and it seems to work fine.

In the phoebus/app/alarm/Readme.md, simply ignore all the references to zookeeper.
There is no config/zookeeper.properties to adjust, and no zookeeper to start, rest is fine.

Can anybody test the alarm logger?

If the alarm code and our currently used kafka client indeed works fine with both the zookeeper-based and the newer kafka server, I suggest to keep it like this for a while to have compatibility.