multikeyToCrypto(keys: Multikey): Promise<CryptoKeyPair>
Convert a multikey pair to Web Crypto. This function decodes the multikey data into JWK using the
multikeyToJWK function, and imports the resulting keys into Web Crypto.
Works for ecdsa (both P-384 and P-256), and eddsa.
Note that, because WebCrypto methods are asynchronous, so is this function.
keys: Multikey
Promise<CryptoKeyPair>