Don't rely on token for scopes collection actions
This requires `scope_id` to be passed (via query param) for actions on
the scopes collection; that is, listing or creating. However, it removes
the dependency on using the token for the scope of the command. For
actions on a specific scope, we use the given ID to determine the scope
we should be operating at, doing a lookup if necessary.
Existing tests have been updated. Of particular note, the CORS test was
already operating on the scopes collection so served as a good test to
ensure that from an API level the scope_id parameter was being parsed
and passed through (the tests fail without adding that query parameter
in).
Jeff Mitchell