fix export * warning for client pages (#3795)
This gets rid of this warning when using a client component as page:
```
warning - [analyze] [project-with-next]/src/app/client/page.jsx unexpected export *
export * used with module [project-with-next]/src/app/client/page.jsx which has no exports
Typescript only: Did you want to export only types with `export type { ... } from "..."`?
```
* fix export * warning for client pages
* Detect `__turbopack_export_value__` as CJS style exports
* fix `__turbopack_cjs__` name
* flag turbopackHelper in client proxy
