Current RocksDBConfigSetter has the following API:
Where `Options` contains configurations for both db-level and cf-level of RocksDB.
As we move on to have multiple CFs following KIP-258, it's better to refactor it into
And then inside the internal implementation, if only the default CF is used, we can still use the other constructor of `Options` that takes both a DBOptions and CFOptions object as parameters.
This should be started only after KIP-258 is finished.