Add codemod for removing `unstable_` prefix (#84974)
Stacked on https://github.com/vercel/next.js/pull/84877,
https://github.com/vercel/next.js/pull/84880
This PR adds a codemod for removing the `unstable_` prefix for
stabilized APIs. It is considered to scale by adding more APIs to the
`UNSTABLE_TO_STABLE_MAPPING` map in the future to this codemod.
Closes NEXT-4739
