ESdriver cleanup

[Yongyao]

@quintinali Can you move these two searchbyQuery() used by datasetDetail to somewhere else. Maybe a separate class in search package. It's bit messy here.

https://github.com/mudrod/mudrod/blob/master/core/src/main/java/esiptestbed/mudrod/driver/ESDriver.java#L249

[lewismc]

yes it is. We should have a separate ESDriverSearch class.

[quintinali]

Ok. I will let you know after I do the modification.

[lewismc]

The purpose of this issue is to introduce a MudrodDriver.java interface, and for ESDriver.java to begin implementing some of the functions. This is the way it should have been implemented originally. The same should be true for SparkDriver.java. It should merely implement MudrodDriver.java