메시지 서명 기능
let signature: String = try await fncyWallet.postWalletSign( wid: 10000, dataToSign: "0x1234...", // signType: "ethSign", //Sign Type pinNumber: "123456" //지갑 비밀번호 )
ethSign : eth_sign
ethSignV2 :
ethSignPersonalWithPrefix :
ethSignWithoutPrefix :
signEip712StructuredData :