fix(ext/node): improve X509Certificate Node.js compatibility (#32671)
## Summary
- Fixes multiple compatibility issues with `crypto.X509Certificate` to
pass the Node.js `test-crypto-x509.js` test suite
- Adds `isX509Certificate()`, `signatureAlgorithm`,
`signatureAlgorithmOid` getters
- Fixes `emailAddress` label, date timezone format, `toLegacyObject()`
output (Buffer raw, null-prototype objects, infoAccess as structured
object, RSA modulus/exponent format)
- Adds structured clone support for X509Certificate via MessagePort
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Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>