Support automatic detection of crypto for node 19 and above

[justin-tay]

Closes #414

Since Node 19 globalThis.crypto now contains an instance to Crypto. This is still true in Node 22. Prior to Node 19 (eg in Node 18) this it was globalThis.crypto.webcrypto. Note that in Node 18, globalThis.crypto is not an instance of Crypto but contains both a subtle member and a webcrypto member.

See https://nodejs.org/docs/latest-v19.x/api/webcrypto.html#web-crypto-api

This isn't caught by tests as the engine gets initialized separately

PKI.js/test/utils.ts

Lines 53 to 59 in 06f154a

	if (isNode()) {
	import("@peculiar/webcrypto").then(peculiarCrypto => {
	const webcrypto = new peculiarCrypto.Crypto();
	const name = "newEngine";
	pkijs.setEngine(name, new pkijs.CryptoEngine({ name, crypto: webcrypto }));
	});
	}