Split storm-kafka-client KafkaSpoutConfig into a config for the Storm spout and a config for the Trident spouts

The KafkaSpoutConfig class is being used for configuration of both the Trident and non-Trident spouts. I think we should split it up, because about half the properties are only used by the non-Trident spout. It is confusing for users to have a lot of settings that don't do anything.