Current behavior is that you need list grant on the parent scope when
recursively listing, and this is sufficient. This is good for
administrative workflows but can be unintuitive for resources that only
exist at a project level. This change allows permissions on the child
scope to also be taken into account, so that you can start a recursive
list from a parent scope without direct list support on that scope but
still get back child scopes for which list access is granted.
This also fixes a bug where visibility of a scope for recursive listing
would be based on whether the user had list resources for roles within
that scope instead of for the resource type in question.
