message: Add serial to gettransaction rpc debug info.
diff: @@ -2436,6 +2436,12 @@ static UniValue gettransaction(const JSONRPCRequest& request)
  obj_vin.pushKV("is_mine_ki", pwalletAnon->IsMyAnonInput(txin));
  } else if (txin.scriptSig.IsZerocoinSpend()) {
  obj_vin.pushKV("type", "zerocoinspend");
  + auto spend = TxInToZerocoinSpend(txin);
  + if (spend) {
  + auto bnSerial = spend->getCoinSerialNumber();
  + obj_vin.pushKV("serial", bnSerial.GetHex());
  + obj_vin.pushKV("serial_hash", GetSerialHash(bnSerial).GetHex());
  + }
  } else {
  //Have to specifically look up type to determine whether it is CT or Basecoin
  uint256 hashBlock;
  