API: Broker Model to contain the kafka version of the broker

[nareshv]

Not sure if its possible to include the version # of the broker as part of the Broker Model so that JSON response consumers can leverage this.

[sudoa]

Do you mean the Kafka API version or the internal Kafka release version?

[sudoa]

We discussed two ways to do this.
Method 1: infer broker version from ApiVersion. KIP-35 provided endpoint for ApiVersion. However, this could be inaccurate and also does not account for hot fixes.
Method 2: get version and commit info from JMX. KIP-278 provided an executable to query AppInfo to get version info. Since JMX port might not be available, we need to either add an endpoint to retrieve the information or report it in metricsreporter.
The final solution is pending further investigation.