UX: Revamp category security tab (PR #11273)

Default (public) category on desktop: image

Restricted category on mobile:


If the user removes all groups, access to the category will be restricted to staff.



It’s slightly cleaner to use Ember’s underscore() here.

The global find should not be used anymore. queryAll is the correct way which I see you’ve removed here - was it causing problems?

        everyone_has_access: "This category is public. Everyone can see, reply, and create posts. To restrict permissions, remove one or more of the permissions granted to the \"everyone\" group."