Verifies the client is authorized to authenticate with the server
Arguments:
- account: The client account address
- home_domain: The home domain
- web_auth_domain: The server's domain
- web_auth_domain_account: The server's SIGNING_KEY
- client_domain: The client domain (optional)
- client_domain_account: The client domain's SIGNING_KEY (optional)
- nonce: A random string generated by the server to prevent replay attacks
fn web_auth_verify(
env: soroban_sdk::Env,
args: soroban_sdk::Map,
) -> Result<(), WebAuthError>