Support hash serialization using the new EVP_MD_CTX_serialize/EVP_MD_CTX_deserialize APIs (OpenSSL 4)

[qmuntal]

OpenSSL 4 added support for serializing the hash state using EVP_MD_CTX_serialize and EVP_MD_CTX_deserialize.

We should use it, when available, instead of doing unsafe hacks, like assuming a specific memory layout, or using provider specific methods (like in symcrypt).