Currently Next.js exposes internal code in the error overlay if certain errors were created from the user code. Some examples were attached in #20776.

We can clearly see that the path is wrong (`../next-server`), it should be `./node_modules/next/dist/next-server`:

![CleanShot 2021-03-19 at 01 33 04](https://user-images.githubusercontent.com/3676859/111670728-1ae7e400-8853-11eb-9213-3b359798900e.png)

The root cause is the `__nextjs_original-stack-frame` middleware resolves the file path with the following code:

```js
path.resolve(
  rootDirectory,
  getSourcePath(sourcePosition.source)
)
```

where `rootDirectory` is the **app root**, but `sourcePosition.source` comes from the module path, which is relative to the path of the `next` binary, not the app root. 

That explains why we see `../next-server` from the error above, because it's relative to `./node_modules/next/bin/next`.

Because of that, the resolved result will never have `node_modules` in its path and it won't be filtered by the error overlay in the UI. Here's a screenshot of the frame object in the UI:

![CleanShot 2021-03-18 at 23 01 29@2x](https://user-images.githubusercontent.com/3676859/111670062-65b52c00-8852-11eb-9293-3a6e5b7c4b9b.png)

And the filter we use to determine if a frame is expanded or not only depends on `body.originalStackFrame`:

```js
expanded: !Boolean(
  body.originalStackFrame?.file?.includes('node_modules') ?? true
)
```

So this PR also adds `source.file` check to ensure they will be ignored (not necessary because we fixed the path resolving).

Fixes #20776.