Improve service plan visibility check (readable orgs) (#4217)

When checking for the visibility of plans in readable orgs (SELECT 1 AS
"one") neither potential duplicates nor the order of entries are
important.

Author: philippthun

app/fetchers/service_plan_visibility_fetcher.rb

@@ -5,27 +5,28 @@ def initialize(permission_queryer)
     end
 
     def fetch_orgs(service_plan_guids:)
-      orgs_query(service_plan_guids:).all
+      base_query(service_plan_guids:).
+        select_all(:organizations).
+        distinct(:organizations__id).
+        order_by(:id).
+        all
     end
 
     def any_orgs?(service_plan_guids:)
-      orgs_query(service_plan_guids:).any?
+      base_query(service_plan_guids:).any?
     end
 
     private
 
-    def orgs_query(service_plan_guids:)
+    def base_query(service_plan_guids:)
       dataset = Organization.dataset.
                 join(:service_plan_visibilities, organization_id: :organizations__id).
                 join(:service_plans, id: :service_plan_visibilities__service_plan_id).
                 where(service_plans__guid: service_plan_guids)
 
       dataset = dataset.where(organizations__guid: @permission_queryer.readable_org_guids_query) unless @permission_queryer.can_read_globally?
 
-      dataset.
-        select_all(:organizations).
-        distinct(:organizations__id).
-        order_by(:id)
+      dataset
     end
   end
 end