chore: Rename ControllerMessenger to Messenger

Rename the `ControllerMessenger` to `Messenger` so that it is clear it
can be used for more than just controllers.

This was decided by this ADR: https://github.com/MetaMask/decisions/blob/main/decisions/core/0001-messaging-non-controllers.md

Previous names have been preserved as aliases to avoid making this a breaking
change.

Relates to #4538

packages/base-controller/CHANGELOG.md

@@ -7,6 +7,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- Rename `ControllerMessenger` to `Messenger` ([#5050](https://github.com/MetaMask/core/pull/5050))
+  - `ControllerMessenger` has been renamed to `Messenger`
+  - `RestrictedControllerMessengerConstraint` has been renamed to `RestrictedMessengerConstraint`
+  - `RestrictedControllerMessenger` has been renamed to `RestrictedMessenger`
+  - The `RestrictedMessenger` constructor parameter `controllerMessenger` has been renamed to `messenger`, though the old name is still accepted
+  - The old names remain exported as deprecated aliases of the new names, so this is not a breaking change.
+
 ## [7.0.2]
 
 ### Changed

packages/base-controller/src/BaseControllerV1.test.ts

@@ -16,7 +16,7 @@ import {
   countControllerStateMetadata,
   getCountMessenger,
 } from './BaseControllerV2.test';
-import { ControllerMessenger } from './ControllerMessenger';
+import { ControllerMessenger } from './Messenger';
 
 const STATE = { name: 'foo' };
 const CONFIG = { disabled: true };

packages/base-controller/src/BaseControllerV2.test.ts

@@ -14,8 +14,8 @@ import {
   getPersistentState,
   isBaseController,
 } from './BaseControllerV2';
-import { ControllerMessenger } from './ControllerMessenger';
-import type { RestrictedControllerMessenger } from './RestrictedControllerMessenger';
+import { ControllerMessenger } from './Messenger';
+import type { RestrictedControllerMessenger } from './RestrictedMessenger';
 
 export const countControllerName = 'CountController';
 

packages/base-controller/src/BaseControllerV2.ts

@@ -6,11 +6,11 @@ import type {
   BaseControllerV1Instance,
   StateConstraint as StateConstraintV1,
 } from './BaseControllerV1';
-import type { ActionConstraint, EventConstraint } from './ControllerMessenger';
+import type { ActionConstraint, EventConstraint } from './Messenger';
 import type {
   RestrictedControllerMessenger,
   RestrictedControllerMessengerConstraint,
-} from './RestrictedControllerMessenger';
+} from './RestrictedMessenger';
 
 enablePatches();