Add nonce to FTI interface (#155)

Closes #154

Author: DefiCake

.changeset/four-lizards-tell.md

@@ -0,0 +1,5 @@
+---
+'@fuel-bridge/solidity-contracts': patch
+---
+
+Add nonce to FTI interface

packages/solidity-contracts/contracts/fuelchain/FuelMessagePortal/IFuelMessagePortal.sol

@@ -6,7 +6,7 @@ import {FuelMessagePortalV3} from "./v3/FuelMessagePortalV3.sol";
 /// @notice to be used by external tools, like the block producer
 /// @dev marked abstract to track all relevant current and future functions as development evolves
 abstract contract IFuelMessagePortal is FuelMessagePortalV3 {
-    event Transaction(uint64 max_gas, bytes canonically_serialized_tx);
+    event Transaction(uint256 indexed nonce, uint64 max_gas, bytes canonically_serialized_tx);
 
     function sendTransaction(uint64 gas, bytes calldata serializedTx) external payable virtual;