crypto: fix crash when calling digest after piping

When piping data into an SHA3 hash, EVP_DigestFinal_ex is called in
hash._flush, bypassing safeguards in the JavaScript layer. Calling
hash.digest causes EVP_DigestFinal_ex to be called again, resulting
in a segmentation fault in the SHA3 implementation of OpenSSL.

A relatively easy solution is to cache the result of calling
EVP_DigestFinal_ex until the Hash object is garbage collected.

PR-URL: https://github.com/nodejs/node/pull/28251
Fixes: https://github.com/nodejs/node/issues/28245


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>