NextJS testing & support

Nextjs is a popular frontend framework and there are no tests available for it here. I've tried importing a lit web component that imports pngs using @lit-labs/react with no success due to Next's image processing quirks.

I got stopped by this error
```TypeError: Unknown file extension ".png" for /Users.../assets/user-black.png```

Then by this error after adding 'next-images' to my next.config.js
```Image import "../../../assets/lock-black.png" is not a valid image file. The image may be corrupted or an unsupported format.```

Maybe there needs to be a @lit-labs/next specific wrapper package that aids in the loading of images for Next esm or some documentation on how to configure next.config.js to make this work