[babel-plugin] Support ESM module resolution

### Describe the feature request

The web is moving away from CommonJS, and StyleX is currently the only reason I still need to distribute my libraries in CommonJS.

Tooling gets significantly simpler once I can drop CommonJS support, so I’m hoping you can support ESM soon—if it doesn’t introduce too much complexity on your side.

```js
[
"@stylexjs/babel-plugin",
{
unstable_moduleResolution: {
type: "ESM"
}
}
]
```

Looking forward, thanks!