By scoping the finds to the user, we can avoid a lot of grants_right
lookups and the associated db queries. This is especially helpful for
users who belong to a lot of groups or courses.
Change-Id: I31e22ecddf9456734d6c1297d776a8353e43a526
Reviewed-on: https://gerrit.instructure.com/2486
Tested-by: Hudson <hudson@instructure.com>
Reviewed-by: Zach Wily <zach@instructure.com>