[extended tests]

Original text:
    Use BUF_strlcpy() instead of strcpy().
    Use BUF_strlcat() instead of strcat().
    Use BIO_snprintf() instead of sprintf().
    In some cases, keep better track of buffer lengths.
    This is part of a large change submitted by Markus Friedl <markus@openbsd.org>
Reviewed-by: NTim Hudson <tjh@openssl.org>
Reviewed-by: NPaul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/3701)