Use http server for file references in chrome.app

[gidztech]

The static file server was previously added to the Docker target (#461), but it also needed to be added to the app target (for when you need to run Loki without Docker, e.g. in CI). I have copied the relevant changes over and moved shared modules into core.

Fixes #471 and #465

[gidztech]

@oblador Not sure about the unit test failing. It doesn't seem to be able to get a port in the lambda container.

[gidztech]

@oblador I tweaked solution to not use static file server with lambda renderer as I think there's some networking thing to solve. Rather than try to solve that now, I opted for fixing it it for chrome.app target to try and unblock everyone using that. That way there's no new breaking changes.

I think the Docker tests are a bit flaky. The same failure on the last master branch commit, so nothing introduced here. Not able to re-run them on the PR.

[qooban]

@gidztech Thanks for providing the fix. @oblador #465 is one of the blockers for us to upgrade to Storybook 7, so I'm interested in this PR to be merged and new version of Loki to be released. Let me know if I could help somehow in speeding up that process.

[TudorTacal]

Hi team, any progress on this? It'd be nice to use Loki with Storybook 7 without any of the issues. Thank you.