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 (2025-09-09 14:29:31 GIT hash 98644f8f651c2101a0730cfe31c5807993b7603b built by fridi@fzen)
lowercase letters, non alphabet characters, line breaks, uneven length cause errors