state/apiserver/common: refactor AuthAlways

This branch prepares for an upcoming change to make AuthAlways more strict by splitting `AuthAlways(true/false)` into two helpers, `AuthAlways` and `AuthNever` which take no arguments.

As the value passed to `AuthAlways`was a constant in all but one case this has made the code easier to read in the common case.
Given that the functions returned by AuthAlways and AuthNever are static and don't close over anything would there be a performance benefit in defining them once outside of the function instead of creating new ones for each call?

I don't think there's any real need to change what you've done. I'm just curious.