Clean up `require.cache` handling (#68743)
Follow-up from #68535.
Since the `require.cache` handling is not specific for Webpack, we move the helper functions out of `webpack/plugins/nextjs-require-cache-hot-reloader.ts`.
In addition, when deleting an entry from the `require.cache`, while cleaning up its references in the `children` of parent modules, we now consider all entries in the `require.cache` instead of relying on a list of "origin modules". This list had entries that were not needed, most notably the server runtime bundles (the experimental runtimes were even missing), and at least one (`node-manifest-loader`) was also missing.
This has a negligible effect on performance. Handling 1200 `require.cache` entries takes 0.3ms on an M2. The approach was also previously aligned with @sokra.
