Turbopack: content-hash PageLoaderAsset (#81450)
Closes PACK-5035
- [x] Content hash chunks such as `static/chunks/pages/404.js` with `static/chunks/19a8e82e8f.js` instead
- [x] Including the actual path in `_buildManifest.js`
- [x] Update tests to check the path specified in the manifest
