signData method
Sign data message with key it was called on.
signatureId is Transport.getSignatureId.
signInput can be get from SeedKey.signInput.
Implementation
@override
Future<SignedData> signData({
required String data,
required SignInput signInput,
required int? signatureId,
}) =>
keyStore.signData(data: data, input: signInput, signatureId: signatureId);