idn2_to_ascii_4i issues

hello! i've been looking through your sources and found some issues https://gitlab.com/libidn/libidn2/-/blob/49fe79c77f6013356920b46bd07f95bcb609f541/lib/lookup.c#L741-746

first issue being wrong error code. function returns IDN2_TOO_BIG_DOMAIN but according to error code descriptions, IDN2_TOO_BIG_LABEL was meant

 * @IDN2_TOO_BIG_DOMAIN: Domain name longer than 255 characters.
 * @IDN2_TOO_BIG_LABEL: Domain label longer than 63 characters.

and second issue being NULL-terminator not being copied

i see this function is deprecated, but i think this issues could be fixed anyway