Summary:
soft_pending_compaction_bytes_limit and hard_pending_compaction_bytes_limit are added to BuildColumnfamilyOptions.
Closes https://github.com/facebook/rocksdb/pull/3823

Differential Revision: D7909246

Pulled By: maysamyabandeh

fbshipit-source-id: 89032efbf6b5bd302ea50cbd7a234977984a1fca