[1838] Changing prefetch and preload options (resourceHints)

Currently under the render section of nuxt.config.js there is an option resourceHints (boolean), which enabled (default) or disabled (by setting to false) which, based on the documentation:

Adds prefetch and preload links for faster initial page load time.

I have a rather large list of routes, and some routes that are only used by users that have certain roles/privileges.

It would be nice if:

• prefetch could be disabled, while still having preload (for things like the common chunks) enabled.
• Set a flag in the pages (similar to how scrollToTop is flagged), to enable/disble preload or, prefetch. for that particular page component
• Specify chunknames (or grouping) for a set of routes (i.e. via the page component definition) to group several small pages into the same webpackChunkName file

99% of the my users cannot access administrative pages, so it is kind of a waste of b/w to pre-fetch those pages which will never be loaded by those users, without having to disable site-wide pre-fetching (which affects 100% of the users)

An other option would be able to group pre-fetches by a user speified parameter... say if someone accesses /admin (and isn't re-directed/blocked by middleware), then all the child routes of `/admin would be listed/added in the head as prefetch links.