CDK-417: Remove id partitioner class, cardinality.

This deprecates the builder methods that required class.
CDK-413: Add nullable handling in CSV schema inference.
Add CLI command to create a partition strategy.

This adds "partition-by" to create a partition strategy and validate it
against a schema. For example:
  ./dataset partition-by favoriteColor:hash[16] \
                         favoriteColor:copy \
                         -s user.avsc

Hash, id (copy), and time partition functions are supported.
CDK-401: Add partition option to CLI create command.