tls: include elliptic curve X.509 public key info

X.509 certs are provided to the user in a parsed object form by a number
of TLS APIs. Include public key info for elliptic curves as well, not
just RSA.
- pubkey: the public key
- bits: the strength of the curve
- asn1Curve: the ASN.1 OID for the curve
- nistCurve: the NIST nickname for the curve, if it has one

PR-URL: https://github.com/nodejs/node/pull/24358


Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>