* Rename partition spec fields
Rename partition spec fields to be consistent across the various types
(hashed, single_dim, dynamic). Specifically, use targetNumRowsPerSegment
and maxRowsPerSegment in favor of targetPartitionSize and
maxSegmentSize. Consistent and clearer names are easier for users to
understand and use.
Also fix various IntelliJ inspection warnings and doc spelling mistakes.
* Fix test
* Improve docs
* Add targetRowsPerSegment to HashedPartitionsSpec