Add support for md-less signature schemes in CMS

Add support for md-less signature schemes in CMS

Signature schemes like Ed25519 or ML-DSA use "pure" signing,
i.e. they directly sign the tbs data instead of signing a digest.

This is already supported in the X509 code, but not in CMS.
This commit adds support for such schemes to CMS.

This is a minimalistic set of changes, based in the work done
by David von Oheimb.

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Saša Nedvědický <sashan@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/26867)