refactor: rename amount to fee in fee withdrawal logic and related events

Author: cctdaniel

target_chains/ethereum/contracts/contracts/pyth/PythGovernance.sol

@@ -39,7 +39,7 @@ abstract contract PythGovernance is
         address newWormholeAddress
     );
     event TransactionFeeSet(uint oldFee, uint newFee);
-    event FeeWithdrawn(address targetAddress, uint amount);
+    event FeeWithdrawn(address targetAddress, uint fee);
 
     function verifyGovernanceVM(
         bytes memory encodedVM
@@ -260,14 +260,12 @@ abstract contract PythGovernance is
     }
 
     function withdrawFee(WithdrawFeePayload memory payload) internal {
-        if (payload.amount > address(this).balance)
+        if (payload.fee > address(this).balance)
             revert PythErrors.InsufficientFee();
 
-        (bool success, ) = payload.targetAddress.call{value: payload.amount}(
-            ""
-        );
+        (bool success, ) = payload.targetAddress.call{value: payload.fee}("");
         require(success, "Failed to withdraw fees");
 
-        emit FeeWithdrawn(payload.targetAddress, payload.amount);
+        emit FeeWithdrawn(payload.targetAddress, payload.fee);
     }
 }

target_chains/ethereum/contracts/contracts/pyth/PythGovernanceInstructions.sol

@@ -85,8 +85,8 @@ contract PythGovernanceInstructions {
 
     struct WithdrawFeePayload {
         address targetAddress;
-        // Amount in wei, matching the native uint256 type used for address.balance in EVM
-        uint256 amount;
+        // Fee in wei, matching the native uint256 type used for address.balance in EVM
+        uint256 fee;
     }
 
     /// @dev Parse a GovernanceInstruction
@@ -266,7 +266,7 @@ contract PythGovernanceInstructions {
         uint64 expo = encodedPayload.toUint64(index);
         index += 8;
 
-        wf.amount = uint256(val) * uint256(10) ** uint256(expo);
+        wf.fee = uint256(val) * uint256(10) ** uint256(expo);
 
         if (encodedPayload.length != index)
             revert PythErrors.InvalidGovernanceMessage();

target_chains/ethereum/contracts/forge-test/PythGovernance.t.sol

@@ -705,5 +705,5 @@ contract PythGovernanceTest is
         address newWormholeAddress
     );
     event TransactionFeeSet(uint oldFee, uint newFee);
-    event FeeWithdrawn(address recipient, uint256 amount);
+    event FeeWithdrawn(address recipient, uint256 fee);
 }