CDK-700 - Add HiveServer to minicluster

This starts HiverServer2 as a part of the Hive service. I've also included a few more fixes that were needed to run the minicluster embedded in a webapp, which I've tested here: https://github.com/tomwhite/kite-example/tree/minicluster.
In the descriptor builder, we usually read the file immediately to fail fast. I think it would be better to move the reader code here for the same reason. It could also be reused more easily.