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

[DDDDDanica]

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:
Removed - app/scripts/controllers/detect-tokens.js

[MajorLift]

Heads up on some items here that overlap with Shared Libraries work (cc. @desi):

• app/scripts/controllers/swaps.js: Convert SwapsController to Typescript #23563
  • Making SwapController Amon Hen ready is a high-priority Q2 OKR (O1/KR1) for Shared Libraries.
  • TypeScript conversion is the first step in that epic, so we'll be trying to complete this task ASAP.
• app/scripts/controllers/ens/index.js: This file no longer exists. TypeScript conversion of EnsController was completed by feat: replace EnsController with core implementation #23224