graphql: Only the owner or org member can view saved search
Created by: ryanslade
Specifically, this change disallows site admins the ability to view any saved search.
CheckOrgAccess
was also renamed to CheckOrgAccessOrSiteAdmin
to make it
more explicit that site admins are allowed access. CheckOrgAccess
now does
not allow site admins by default.
Part of https://github.com/sourcegraph/sourcegraph/issues/20800
Saved search listing will be fixed in another PR