submit method
Implementation
Future<XRPLTransactionResult> submit(String txBlob,
{bool failHard = false}) async {
final Map<String, dynamic> configParams = {};
createRpcConfig(configParams, "tx_blob", txBlob);
createRpcConfig(configParams, "fail_hard", failHard);
final response =
await makeCustomCall<Map<String, dynamic>>("submit", [configParams]);
return XRPLTransactionResult.fromJson(response);
}