[php-src] PR #24096: ext/openssl: Support detached signatures with S/MIME encoding

Pull Request: https://github.com/php/php-src/pull/24096 Author: adapik openssl_cms_sign(): support detached signatures with S/MIME encoding OPENSSL_CMS_DETACHED with the default S/MIME encoding was rejected with a warning. But it works perfectly in openssl: openssl cms -sign -in msg.txt -signer cert.pem -inkey key.pem -out signed.eml It can work in PHP as well: this PR adds CMS_STREAM (as the OpenSSL CLI does) makes SMIME_write_CMS() produce a multipart/signed message. openssl_cms_verify() already reads such messages. Only its warning for a separate $signature_filename with S/MIME is reworded, as it no longer claims that detached signatures are impossible.