Add more `bytes->bytes` compression codecs.

[zoj613]

Currently we only support Crc32c and Gzip codecs, since they are the only ones defined in the specification. However nothing is stopping this project from supporting more bytes -> bytes codecs. Ocaml provides a few libraries to help implement them:

• zstd and zstandard for Zstd codec.
• snappy for the Snappy codec.
• ezgzip for Zlib.
• camlbz2 for Bz2