This change both speeds up specs (less strings to allocate) and helps catch
cases where methods in Discourse are mutating inputs.
Overall we will be migrating everything to use #frozen_string_literal: true
it will take a while, but this is the first and safest move in this direction
previously we supported blanket read and write for user API, this
change amends it so we can define more limited scopes. A scope only
covers a few routes. You can not grant access to part of the site and
leave a large amount of the information hidden to API consumer.
