Fix MJS issues

[ysulyma]

Thanks for the library. This PR fixes ~two~ three issues I was encountering:

• the Next bundler couldn't understand the types.mjs file since it didn't export anything; changing to export type * removes this export from the emitted JS
• adds .mjs extensions to imports as required by ESM (somehow my code was loading both the ESM and CJS versions, and then complaining that it couldn't find <CookiesProvider>)
• rewrite import { /* ... */ } from "next/navigation" to import { /* ... */ } from "next/navigation.js"

Your original code was working for me at one point, so I don't know why it suddenly started breaking, and I wasn't able to put together a minimal repro. These are all how ESM is supposed to work though.

[moshest]

I'm not sure what's wrong in your setup. It usually common to import from "next/navigation" and not from "next/navigation.js" so I can't approve this PR. Same apply for the esbuild rewrite script.

Happy to approve the export type * fix for the types.ts file.