apps/passwd.c: Make MD5 and SHA password making EBCDIC aware

This mimics the behaviour of DES_crypt, where the salt and password
are expected to be in EBCDIC when CHARSET_EBCDIC is defined, and are
converted internally to ASCII.  This is also done with the magic ID
string if it's not already ASCII.  The resulting output is entirely
built up of ASCII components and is converted back to EBCDIC at the
end.

Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/4229)