use chunks for service-worker target

[pi0]

nuxt/nuxt#11779

We can use renderDynamicImport (todo) to load async chunks for server-worker target instead of using one chunk with either fetch+eval or importScripts. This will allow us deploying a real world app (like docus transformers) to static hosting without huge startup time.

Alternative: We can also use experimental ES worker modules (blog) but I think last time there was a chrome only support for this and firefox was unable