utility method getDigest() to support WARC digest algorithm names which are not valid Java MessageDigest identifiers - eg. sha256 needs to be SHA-256, otherwise a NoSuchAlgorithmException is thrown
support for padding of Base32 encoded digests
add support for Base64 digest encoding
auto-detect encoding of digests by value length when parsing digest strings in WARC files, convert to Base32 if needed
getDigest()to support WARC digest algorithm names which are not valid Java MessageDigest identifiers - eg.sha256needs to beSHA-256, otherwise a NoSuchAlgorithmException is thrown