Allows multiple lines for `Module not found` errors (#10797)

Next is currently removing useful information from the PnP error messages.

Before:

```
Module not found: Something that got detected as your top-level application (because it doesn't seem to belong to any package) tried to access a package that is not declared in your dependencies
```

After:

```
Module not found: Something that got detected as your top-level application (because it doesn't seem to belong to any package) tried to access a package that is not declared in your dependencies

Required package: foo (via "foo/components/Avatar")
Required by: /home/arcanis/foo/bar.tsx
```

packages/next/client/dev/error-overlay/format-webpack-messages.js

@@ -86,6 +86,7 @@ function formatMessage(message) {
       lines[1]
         .replace('Error: ', '')
         .replace('Module not found: Cannot find file:', 'Cannot find file:'),
+      ...lines.slice(2).filter((line) => line.indexOf(' @ ') !== 0),
     ]
   }