HPCC-10617 Add support for Cassandra

Added support for SET parameters and dataset fields

Signed-off-by: Richard Chapman <rchapman@hpccsystems.com>
HPCC-10617 Add support for Cassandra

Minor changes following code review

Signed-off-by: Richard Chapman <rchapman@hpccsystems.com>
Merge pull request #6378 from richardkchapman/cassandra-sets

HPCC-10617 Add support for Cassandra

Reviewed-By: Jake Smith <jake.smith@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>