Summary:
* Started on some proper usage text to document the options
* Added a `JOB_ID` parameter, so that we can trace jobs and relate them to other assets
* Now generates a correct TSV file of the summary
* Summary has new additional fields:
* RocksDB Version
* Date
* Job ID
* db_bench log files now also include the Job ID
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8730
Reviewed By: mrambacher
Differential Revision: D30747344
Pulled By: jay-zhuang
fbshipit-source-id: 87eb78d20959b6d95804aebf129606fa9c71f407