Restore owner filtering for consumer principals.
Drop the READ_SUBSCRIPTIONS access level in favor of sub-resource.
Allow system admins to still create and list org consumers.
Refactor Access level logic.

Moved the multiple copies of providesAccess onto Access enumeration
itself. Assigned each access level an integer so we can do actual
comparisons. Read-only is the lowest with 1, all the others are higher
with ALL being the highest, and thus providing everything below.
Expand tests and fix issues with system admin permissions.

Add more fine grained permissions that allow a system administrator to
list pools and subscribe for their systems only.
Add ability for trusted auth to still lookup user permissions.

If the cp-lookup-permissions header is passed in addition to cp-user,
the TrustedAuth implementation will still query the user service for a
user object.

The user will carry specific permissions which will appear on the
UserPrincipal created as a result.

If the header is not specified we perform trusted auth as before.