Remove Native Dependencies

BnkExtractor currently relies on [OggVorbisSharp](https://github.com/SamboyCoding/OggVorbisSharp), a managed wrapper for [Ogg](https://github.com/xiph/ogg) and [Vorbis](https://github.com/xiph/vorbis). In order for this to eventually be used in AssetRipper, that dependence must be removed.