Avoid usage of Session.execute String - Non-Idempotent Requests

We need to double check all of our usages of session.execute("String") because of the driver's behavior with idempotentcy.

In particular

https://github.com/datastax/spark-cassandra-connector/blob/993bdd9d946fa49871abdadbb09982e177b2923d/connector/src/main/scala/com/datastax/spark/connector/rdd/partitioner/dht/TokenFactory.scala#L99

Is preformed only a single time so an attempt to look up the token factory name can fail once and never be retried. In pretty much all cases like this we need to build a statement and set idempotency to true.