improve(SpokePool): Delete chainId in ExecutedV3RelayerRefundRoot event (#424)

chainId is not useful because it is known based on the SpokePool being
queried. Also, the marginal value of indexing the leafId on top of the
rootBundleId is pretty minimal, so instead index l2TokenAddress and
fillsRefundedRoot.

Authored by Nick & cherry-picked by me.

Author: pxrl

contracts/SpokePool.sol

@@ -1352,7 +1352,6 @@ abstract contract SpokePool is
 
         emit ExecutedV3RelayerRefundRoot(
             relayerRefundLeaf.amountToReturn,
-            relayerRefundLeaf.chainId,
             relayerRefundLeaf.refundAmounts,
             rootBundleId,
             relayerRefundLeaf.leafId,

contracts/interfaces/V3SpokePoolInterface.sol

@@ -178,13 +178,12 @@ interface V3SpokePoolInterface {
 
     event ExecutedV3RelayerRefundRoot(
         uint256 amountToReturn,
-        uint256 indexed chainId,
         uint256[] refundAmounts,
         uint32 indexed rootBundleId,
-        uint32 indexed leafId,
-        address l2TokenAddress,
+        uint32 leafId,
+        address indexed l2TokenAddress,
         address[] refundAddresses,
-        bytes32 fillsRefundedRoot,
+        bytes32 indexed fillsRefundedRoot,
         string fillsRefundedHash
     );
 

test/SpokePool.ExecuteRootBundle.ts

@@ -261,7 +261,6 @@ describe("SpokePool Root Bundle Execution", function () {
         .to.emit(spokePool, "ExecutedV3RelayerRefundRoot")
         .withArgs(
           leaves[0].amountToReturn,
-          leaves[0].chainId,
           leaves[0].refundAmounts,
           0, // rootBundleId
           leaves[0].leafId,