Improvements

• #119 The functions proto.Marshal, proto.Unmarshal, and proto.MessageName, as well as the jsonpb marshaling and unmarshaling methods now all support official google.golang.org/protobuf types. This allows users to gradually start using these types instead of gogo proto without needing to refactor all of their code with type switch statements.

Full CHANGELOG: https://github.com/cosmos/gogoproto/blob/main/CHANGELOG.md