ZSTD to use CompressionOptions.level
ZSTD to use CompressionOptions.level

Summary: Now ZSTD hard code level 1. Change it to use the compression level setting.

Test Plan: Run it with hacked codes of sst_dump and show ZSTD compression sizes with different levels.

Reviewers: rven, anthony, yhchiang, kradhakrishnan, igor, IslamAbdelRahman

Reviewed By: IslamAbdelRahman

Subscribers: yoshinorim, leveldb, dhruba

Differential Revision: https://reviews.facebook.net/D52041

Andymic/rocksdb,ryneli/rocksdb,tsheasha/rocksdb,bbiao/rocksdb,tsheasha/rocksdb,hobinyoon/rocksdb,Andymic/rocksdb,OverlordQ/rocksdb,hobinyoon/rocksdb,wat-ze-hex/rocksdb,flabby/rocksdb,ryneli/rocksdb,Andymic/rocksdb,wenduo/rocksdb,vmx/rocksdb,bbiao/rocksdb,wenduo/rocksdb,norton/rocksdb,vmx/rocksdb,SunguckLee/RocksDB,Andymic/rocksdb,hobinyoon/rocksdb,OverlordQ/rocksdb,vmx/rocksdb,SunguckLee/RocksDB,tsheasha/rocksdb,vmx/rocksdb,Vaisman/rocksdb,facebook/rocksdb,facebook/rocksdb,flabby/rocksdb,hobinyoon/rocksdb,Andymic/rocksdb,SunguckLee/RocksDB,wat-ze-hex/rocksdb,vmx/rocksdb,flabby/rocksdb,bbiao/rocksdb,norton/rocksdb,bbiao/rocksdb,Andymic/rocksdb,SunguckLee/RocksDB,hobinyoon/rocksdb,vmx/rocksdb,jalexanderqed/rocksdb,jalexanderqed/rocksdb,Vaisman/rocksdb,jalexanderqed/rocksdb,Vaisman/rocksdb,wenduo/rocksdb,facebook/rocksdb,wat-ze-hex/rocksdb,hobinyoon/rocksdb,tsheasha/rocksdb,wat-ze-hex/rocksdb,flabby/rocksdb,bbiao/rocksdb,SunguckLee/RocksDB,norton/rocksdb,Vaisman/rocksdb,wat-ze-hex/rocksdb,tsheasha/rocksdb,Vaisman/rocksdb,ryneli/rocksdb,ryneli/rocksdb,wenduo/rocksdb,OverlordQ/rocksdb,vmx/rocksdb,wat-ze-hex/rocksdb,facebook/rocksdb,ryneli/rocksdb,OverlordQ/rocksdb,tsheasha/rocksdb,hobinyoon/rocksdb,flabby/rocksdb,bbiao/rocksdb,facebook/rocksdb,ryneli/rocksdb,flabby/rocksdb,OverlordQ/rocksdb,jalexanderqed/rocksdb,jalexanderqed/rocksdb,wenduo/rocksdb,tsheasha/rocksdb,hobinyoon/rocksdb,wat-ze-hex/rocksdb,facebook/rocksdb,norton/rocksdb,facebook/rocksdb,Andymic/rocksdb,vmx/rocksdb,bbiao/rocksdb,ryneli/rocksdb,jalexanderqed/rocksdb,tsheasha/rocksdb,bbiao/rocksdb,SunguckLee/RocksDB,Vaisman/rocksdb,wenduo/rocksdb,norton/rocksdb,OverlordQ/rocksdb,Vaisman/rocksdb,wat-ze-hex/rocksdb,facebook/rocksdb,norton/rocksdb,OverlordQ/rocksdb,SunguckLee/RocksDB,flabby/rocksdb,norton/rocksdb,wenduo/rocksdb,SunguckLee/RocksDB,Andymic/rocksdb,wenduo/rocksdb,jalexanderqed/rocksdb,norton/rocksdb