Extend Wallets to include an AuthSig field

[anthonyra]

I'm interested in the more flexible extension listed at #3 however for my current use case. I'd like the ability to save an AuthSig generated from the Lit Protocol to the ArProfile created with arweave-account. I'm thinking that since this is protocol specific that a JSON extension could be used to implement such a feature? I do like the flexibility of appData but don't think it's needed to implement this part. I would suggest the following change to both T_profile and ArAccountEncoded.

type T_profile | ArAccountEncoded = {
  ...
  wallets: {
    eth?: {
      address: string;
      auth?: {
        litAuthSig?: { // IAW https://lit-protocol.github.io/lit-js-sdk/api_docs_html/#authsig
          sig: string;
          derivedVia: string;
          signedMessage: string;
          address: string;
        }
      }
    }
  }
};

I believe the type upgrade above is all that's needed to implement this additional data field. Let me know if this isn't the case?