Summary:
Right now, in db_stress, compact range is simply executed without any immediate data validation. Add a simply validation which compares hash for all keys within the compact range to stay the same against the same snapshot before and after the compaction.

Also, randomly tune most knobs of CompactRangeOptions.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6140

Test Plan: Run db_stress with "--compact_range_one_in=2000 --compact_range_width=100000000" for a while. Manually ingest some hacky code and observe the error path.

Differential Revision: D18900230

fbshipit-source-id: d96e75bc8c38dd5ec702571ffe7cf5f4ea93ee10