Nested imports are not supported

This code doesn't work:
```javascript
if (Meteor.isServer) {
import { xxx } from 'yyy'
console.log(xxx)
}
```

It would be nice to have this feature. I got around this problem by replacing `import` with `require()` in the existing project, but AFAIK [it's not the same](https://zodern.me/posts/nested-imports/).