Convert partial level 2 files to typescript for contributing to `metamask-controller.js`

Convert dependency of files for metamask-controller.js (level 2) we want to target based on typescript migration dashboard.

**_Level 2_**
- app/scripts/controllers/ens/index.js
- app/scripts/controllers/metametrics.js
- app/scripts/controllers/swaps.js
- app/scripts/lib/ComposableObservableStore.js
- app/scripts/lib/createMetaRPCHandler.js
- app/scripts/lib/createRPCMethodTrackingMiddleware.js

will be tackled by shared library team in [another ticket](https://github.com/MetaMask/metamask-extension/pull/22928):
Removed _- app/scripts/controllers/detect-tokens.js_

Start with the TypeScript migration dashboard and the six listed files: app/scripts/controllers/ens/index.js, metametrics.js, swaps.js, and the three files under app/scripts/lib. Review the linked ticket for the shared-library scope; done means converting the listed level 2 dependencies for metamask-controller.js while leaving detect-tokens.js excluded.

Written by the indexing model from the issue text.