Use extraOptions to set the configuration for Spark Workers

We need a standardized way to set configurations for Spark driver and workers when reading and writing data.

Quoting from my offline discussion with twdsilva@gmail.com:

"if we use phoenixTableAsRDD to create the rdd then we can pass in a config
if we use the standard df.write.format() we can't pass in a conf
maybe the best was to do this is to put config in the option map when we call read/write .format and then set those in the config"