During Skunkworks research on BSONColumn compression with Zstd ( https://docs.google.com/document/d/17YVNNTX7bkNWscRY8xTq6CzZX4-4Xh9ftZ0trwYJ-AQ/edit?usp=sharing ), a command line tool was implemented to get BSONColumn encoded data from BSON inputs.  We should separate this, clean it up,  and add some more flags for control, and check it in, it may be useful for future studies.