Use TYPE_do_all_provided function for listing cipher/digest

Use TYPE_do_all_provided function for listing cipher/digest

With OpenSSL 3.0 the use of nid values is deprecated and new algorithms
do not even have NID values anymore.

This also works nicely with providers now:

   openvpn --provider legacy:default --show-ciphers

shows more ciphers (e.g. BF-CBC) than just

   openvpn --show-ciphers

when compiled with OpenSSL 3.0

Patch v4: Use SIZE instead size(x)/sizeof(*x)

Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20211109144811.3426928-1-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg23142.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>