Added support for extraction of RAR v5 archives

Added support for extraction of RAR v5 archives

This is an initial implementation of a stream-oriented unpacker. Things
that should work:

- Extraction of any compression level (stored or compressed), file
  enumeration, skipping through files,
- Support for any dictionary sizes,
- CRC32 and BLAKE2sp checksums,
- Solid archives,
- Multi-volume archives (part001, part002, etc),
- Solid multi-volume archives,
- DELTA, x86 and ARM filter support: other filters are not used
  in version 5 of the format.

Things that are missing from this implementation:

- Encryption support,
- NTFS ACL permission settings,
- Parsing the Reed-Solomon recovery record.