Revert "Move App Route handler logic into bundle" (#47614)
Reverts vercel/next.js#47582
This breaks turbopack support so we should address that before landing.
Potentially we can re-use the same loader for both which would eliminate
this issue.
x-ref:
https://github.com/vercel/next.js/actions/runs/4544370605/jobs/8010399819
x-ref:
https://github.com/vercel/next.js/actions/runs/4545240650/jobs/8012475072?pr=47611
fix NEXT-712 ([link](https://linear.app/vercel/issue/NEXT-712))
