Better deserialization of query results through the ExploreClient

Solving https://issues.cask.co/browse/CDAP-384:
Instead of including the type information in every cell of every row of results of a query, the ``ExploreClient`` re uses the information of type contained in the result schema, to better deserialize from Json to ``QueryResult`` objects.

Bamboo build: https://builds.cask.co/browse/CDAP-DUT123-1
This was if, say, in some version of Hive, the BINARY type translated to a String, just like the other ARRAY types translate to. But you're right I'll throw an exception for now, and if the case ever pops up we'll deal with it later.