Turbopack: make stats.json useable (#81318)
Make the `.next/server/webpack-stats.json` file that was already getting generated with `TURBOPACK_STATS=1` actually usable with https://statoscope.tech/.
Not the most efficient implementation, but definitely works for small apps.
- Chunks have the parent/child connection (though I can't see that in the UI)
- Modules have the `reasons` set, so the module graph traversal works now. Note that this all ignores scope hoisting though, so there are some modules missing right now in some views
