Add shouldPrefetch() in vue-server-renderer

[laugharn]

What problem does this feature solve?

When using Vue to create a static site (like via nuxt generate) every code split asset is getting prefetched. This is an awesome feature if we were thinking about offline mode, but when you're trying to create a site with triple digit routes and little concern for offline browsing (i.e. a marketing site) this is creating some pretty beefy code overhead.

It would be great if there was a way to get a shouldPrefetch in vue-server-renderer, similar to shouldPreload.

What does the proposed API look like?

Exactly like shouldPreload(), but for prefetching would be great.

[FranckFreiburger]

I agree with @laugharn prefetch resources should be controllable.
In my case, I would like to avoid some big scripts (like PDF.js + PDF.js worker) to be downloaded too early.

[laugharn]

🎉 this is great, thanks @yyx990803