Implement EIP-4361 Sign-In with Ethereum

Android: https://github.com/AlphaWallet/alpha-wallet-android/issues/3113

* EIP-4361: https://eips.ethereum.org/EIPS/eip-4361 in particular the section "Wallet Implementer Steps"
* Test page (Use WalletConnect): https://wagmi.sh/examples/sign-in-with-ethereum

Goal
---
It looks like there could still be changes to the EIP since it's under review, but we can at a minimum do this for all sign personal requests:

```
if message includes "wants you to sign in with your Ethereum account"
validate the entire message as described in the EIP and fail immediately if validation fails
display the title "Sign in with Ethereum" for the actionsheet
display the respective fields
promptToSignPersonalLikeNormal
else
proceedWithPersonalSignNormally
end
```

Now in AlphaWallet
---
It already kind of works since it's signing a personal (text) message, at least with the test page above

Here's how it looks like now:

Desktop Safari:

AlphaWallet: