Summary:
1. Fix GetOptionsPtr for Wrapped (Inner() != nullptr) Customizable objects. This allows the inner options to be returned via this method.
2. Allow the option type map to be nullptr. This allows objects to be registered as options (for GetOptionsPtr) but not be used by the configuration methods.
Added tests as appropriate.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/9213
Reviewed By: zhichao-cao
Differential Revision: D32718882
Pulled By: mrambacher
fbshipit-source-id: 563203d1f006a2629060feb31c5dff9a233e1e83