Support import() local code in extension service worker

I know #1585 discussed import() in service worker. Here I am talking about browser extension service worker.

https://github.com/w3c/webextensions/issues/212 Some developers proposed it in WECG. Unlike Web, all code are already locally and offline available in a browser extension. So dynamically import() local code in extension service worker should just like normal javascript behavior, it should not be a problem for extensions.

According to past meeting minutes, browser vendors are basically supportive of it in extension service worker.

I think there should be no objection to supporting import() in extension service worker. Web may also support import() in service worker in the future, but there will definitely be more considerations and requirements.

Start by reading issue #1585, the linked WECG issue #212, and the 2022-05-26 meeting minutes. Compare their discussion of import() in extension service workers with this request, then determine the specification changes and interoperability expectations needed for support. Done means the desired extension-service-worker behavior and requirements are resolved in the ServiceWorker specification.