chore: Use consistent variable name for messenger (#6957)

## Explanation

Various variables have been renamed from `messagingSystem` to
`messenger` for consistency. These packages have all updated to the next
version of the `BaseController`, which dropped the term
`messagingSystem` in #6337.

## References

N/A

## Checklist

- [x] I've updated the test suite for new or updated code as appropriate
- [x] I've updated documentation (JSDoc, Markdown, etc.) for new or
updated code as appropriate
- [x] I've communicated my changes to consumers by [updating changelogs
for packages I've
changed](https://github.com/MetaMask/core/tree/main/docs/contributing.md#updating-changelogs),
highlighting breaking changes as necessary
- [x] I've prepared draft pull requests for clients and consumer
packages to resolve any breaking changes

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Author: Gudahtt

packages/assets-controllers/src/AssetsContractController.ts

@@ -216,7 +216,7 @@ export type StakedBalance = string | undefined;
 export class AssetsContractController {
   readonly name: typeof name = name;
 
-  protected messagingSystem: AssetsContractControllerMessenger;
+  protected messenger: AssetsContractControllerMessenger;
 
   #provider: Provider | undefined;
 
@@ -238,7 +238,7 @@ export class AssetsContractController {
     messenger: AssetsContractControllerMessenger;
     chainId: Hex;
   }) {
-    this.messagingSystem = messenger;
+    this.messenger = messenger;
     this.#provider = undefined;
     this.#ipfsGateway = IPFS_DEFAULT_GATEWAY_URL;
     this.#chainId = initialChainId;
@@ -251,7 +251,7 @@ export class AssetsContractController {
   #registerActionHandlers() {
     const methodsExcludedFromMessenger = [
       'constructor',
-      'messagingSystem',
+      'messenger',
       'setProvider',
       'provider',
       'ipfsGateway',
@@ -265,7 +265,7 @@ export class AssetsContractController {
             !methodsExcludedFromMessenger.find((e) => e === key) &&
             typeof this[key] === 'function')(method)
         ) {
-          this.messagingSystem.registerActionHandler(
+          this.messenger.registerActionHandler(
             `${name}:${method}`,
             // TODO: Write a generic for-loop implementation that iterates over an input union type in tandem with the input array.
             // @ts-expect-error Both assigned argument and assignee parameter are using the entire union type for `method` instead of the type for the current element
@@ -277,14 +277,14 @@ export class AssetsContractController {
   }
 
   #registerEventSubscriptions() {
-    this.messagingSystem.subscribe(
+    this.messenger.subscribe(
       `PreferencesController:stateChange`,
       ({ ipfsGateway }) => {
         this.#ipfsGateway = ipfsGateway;
       },
     );
 
-    this.messagingSystem.subscribe(
+    this.messenger.subscribe(
       `NetworkController:networkDidChange`,
       ({ selectedNetworkClientId }) => {
         const chainId = this.#getCorrectChainId(selectedNetworkClientId);
@@ -323,11 +323,11 @@ export class AssetsContractController {
    */
   #getCorrectProvider(networkClientId?: NetworkClientId): Web3Provider {
     const provider = networkClientId
-      ? this.messagingSystem.call(
+      ? this.messenger.call(
           `NetworkController:getNetworkClientById`,
           networkClientId,
         ).provider
-      : (this.messagingSystem.call('NetworkController:getSelectedNetworkClient')
+      : (this.messenger.call('NetworkController:getSelectedNetworkClient')
           ?.provider ?? this.#provider);
 
     if (provider === undefined) {
@@ -345,18 +345,18 @@ export class AssetsContractController {
    */
   #getCorrectChainId(networkClientId?: NetworkClientId): Hex {
     if (networkClientId) {
-      const networkClientConfiguration = this.messagingSystem.call(
+      const networkClientConfiguration = this.messenger.call(
         'NetworkController:getNetworkConfigurationByNetworkClientId',
         networkClientId,
       );
       if (networkClientConfiguration) {
         return networkClientConfiguration.chainId;
       }
     }
-    const { selectedNetworkClientId } = this.messagingSystem.call(
+    const { selectedNetworkClientId } = this.messenger.call(
       'NetworkController:getState',
     );
-    const networkClient = this.messagingSystem.call(
+    const networkClient = this.messenger.call(
       'NetworkController:getNetworkClientById',
       selectedNetworkClientId,
     );

packages/bridge-status-controller/src/utils/gas.ts

@@ -62,7 +62,7 @@ export const getTxGasEstimates = ({
 
 export const calculateGasFees = async (
   disable7702: boolean,
-  messagingSystem: BridgeStatusControllerMessenger,
+  messenger: BridgeStatusControllerMessenger,
   estimateGasFeeFn: typeof TransactionController.prototype.estimateGasFee,
   { chainId: _, gasLimit, ...trade }: TxData,
   networkClientId: string,
@@ -82,7 +82,7 @@ export const calculateGasFees = async (
     to: trade.to as `0x${string}`,
     value: trade.value as `0x${string}`,
   };
-  const { gasFeeEstimates } = messagingSystem.call('GasFeeController:getState');
+  const { gasFeeEstimates } = messenger.call('GasFeeController:getState');
   const { estimates: txGasFeeEstimates } = await estimateGasFeeFn({
     transactionParams,
     chainId,

packages/bridge-status-controller/src/utils/transaction.ts

@@ -36,7 +36,7 @@ import type {
 export const generateActionId = () => (Date.now() + Math.random()).toString();
 
 export const getUSDTAllowanceResetTx = async (
-  messagingSystem: BridgeStatusControllerMessenger,
+  messenger: BridgeStatusControllerMessenger,
   quoteResponse: QuoteResponse & Partial<QuoteMetadata>,
 ) => {
   const hexChainId = formatChainIdToHex(quoteResponse.quote.srcChainId);
@@ -45,7 +45,7 @@ export const getUSDTAllowanceResetTx = async (
     isEthUsdt(hexChainId, quoteResponse.quote.srcAsset.address)
   ) {
     const allowance = new BigNumber(
-      await messagingSystem.call(
+      await messenger.call(
         'BridgeController:getBridgeERC20Allowance',
         quoteResponse.quote.srcAsset.address,
         hexChainId,

packages/composable-controller/src/ComposableController.test.ts

@@ -67,9 +67,9 @@ class FooController extends BaseController<
   FooControllerState,
   FooMessenger
 > {
-  constructor(messagingSystem: FooMessenger) {
+  constructor(messenger: FooMessenger) {
     super({
-      messenger: messagingSystem,
+      messenger,
       metadata: fooControllerStateMetadata,
       name: 'FooController',
       state: { foo: 'foo' },
@@ -116,9 +116,9 @@ class QuzController extends BaseController<
   QuzControllerState,
   QuzMessenger
 > {
-  constructor(messagingSystem: QuzMessenger) {
+  constructor(messenger: QuzMessenger) {
     super({
-      messenger: messagingSystem,
+      messenger,
       metadata: quzControllerStateMetadata,
       name: 'QuzController',
       state: { quz: 'quz' },