Add public name property to AssetsContractController class (#4564)

## References

- See #4072

## Changelog

```md
### Added

- Add public readonly property `name` to `AssetsContractController` and assign "AssetsContractController" as its value.
```

## Checklist

- [ ] I've updated the test suite for new or updated code as appropriate
- [ ] I've updated documentation (JSDoc, Markdown, etc.) for new or
updated code as appropriate
- [ ] I've highlighted breaking changes using the "BREAKING" category
above as appropriate

packages/assets-controllers/src/AssetsContractController.ts

@@ -201,6 +201,8 @@ export type AssetsContractControllerMessenger = RestrictedControllerMessenger<
  * Controller that interacts with contracts on mainnet through web3
  */
 export class AssetsContractController {
+  readonly name: typeof name = name;
+
   protected messagingSystem: AssetsContractControllerMessenger;
 
   #provider: Provider | undefined;