Allow creating randomized EdDSA signatures?

[twiss]

The current specification of EdDSA, in RFC 8032 (which we refer to), defines Ed25519 and Ed448 as being deterministic.

WebKit's implementation of Ed25519, when using macOS's CryptoKit, produces randomized signatures as per draft-irtf-cfrg-det-sigs-with-noise, citing security benefits.

So, we may want to allow this as well in the spec.

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This is a copy of WICG/webcrypto-secure-curves#28, to keep track of that issue after we archive WICG/webcrypto-secure-curves.