decodes a base16 string, decoding is strict as required by RFC 4648 lowercase letters, non alphabet characters, line breaks, uneven length cause errors
0.095dev (2025-08-15 12:02:22 GIT hash 301b5b75e77076d091b38f555473f9f0e31e5b5c built by fridi@fzen)
lowercase letters, non alphabet characters, line breaks, uneven length cause errors