Imports inside of injected scripts

[Katel1ne]

Describe the problem

When you use imports inside of injected script, which is imported with "?script&module" you get following error
Uncaught SyntaxError: Cannot use import statement outside a module

Describe the proposed solution

Mostly I would like to see it for cross-layers messaging, which seems to be done by this package
zikaari/crx-bridge#11
Which was later forked as https://github.com/zikaari/webext-bridge
But it would be also handy to import some other utils' functions to share functionality rather then write it all over again for injected scripts.

Alternatives considered

I don't know if it can be achieved with current CRXJS version however, tried few ways w/o any success. If it's already possible - would be nice to see the solution.

Importance

would make my life easier