Enable `export $ from` shorthand

[barneycarroll]

Flems doesn't seem to be able to parse the export ${map} from ${specifier} format.

So this throws:

export {default as sequencer} from './sequencer.js'
export {extensions} from './integrations.js' 

And needs to be achieved with a local imports namespace:

import sequencer from './sequencer.js'
import {extensions} from './integrations.js' 

export {sequencer, extensions}

Live test case