Support calling EVP_DigestUpdate instead of EVP_Digest[Sign|Verify]Update

Support calling EVP_DigestUpdate instead of EVP_Digest[Sign|Verify]Update

Prior to OpenSSL 3.0 EVP_Digest[Sign|Verify|Update were just macros for
EVP_DigestUpdate. They are now separate functions. Unfortunately some
code assumes that EVP_Digest[Sign|Verify]Update is interchangeable with
EVP_DigestUpdate. For example the dgst app uses an MD bio which always
calls EVP_DigestUpdate(). However the dgst app supports signing instead
of digesting and may initialise with EVP_DigestSignInit_ex() instead of
just EVP_DigestInit().

We now detect these differences and redirect to the correct function
where appropriate.

Fixes #10114

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/10116)