ByteString parser improvements

ByteString parser seems to be not usable because there are 0 parser functions operating on ByteString. When we operate on strings of chars we have useful parsers like "oneOf", "digit", "spaces". It would be nice to have something like "zeros"(for bytes filled with zeros), "bigEndiandInt32", "byte" to consume bytes from the ByteString stream and write the results into appropriate data types. Something similar was done in "HCodecs"(and many other places where people try to handle some specific file formats). Parsec would be a more natural place to look for such convenient general functions.