message: p2p: add CInv transaction message helper methods
diff: @@ -430,6 +430,14 @@ public:
  std::string GetCommand() const;
  std::string ToString() const;
  + // Single-message helper methods
  + bool IsMsgTx() const { return type == MSG_TX; }
  + bool IsMsgWtx() const { return type == MSG_WTX; }
  + bool IsMsgWitnessTx() const { return type == MSG_WITNESS_TX; }
  +
  + // Combined-message helper methods
  + bool IsGenTxMsg() const { return type == MSG_TX || type == MSG_WTX || type == MSG_WITNESS_TX; }
  +
  int type;
  uint256 hash;
  };
  