dynamic root folders for dynamic imports inside webpack based builds

cross reference ticket for: https://github.com/webpack/webpack/issues/11483

in case there was a way to specify different folder roots, we could remove the custom app worker build entry point.

we can not use '../../../../../' for everything, since this would slow down the build time by a long shot and create split chunks we don't want.

e.g.: I got the following structure locally:

github

• neomjs
• • neo
• • covid-dashboard
• • realworld

(all sub repos)

walking up too far would create split chunks across the different sub repos.