Allow platform managers to see all public and private events

Author: rsmithlal

app/policies/better_together/event_policy.rb

@@ -37,7 +37,9 @@ def permitted_query
         # Only list communities that are public and where the current person is a member or a creator
         query = events_table[:privacy].eq('public')
 
-        if agent
+        if permitted_to?('manage_platform')
+          query = query.or(communities_table[:privacy].eq('private'))
+        elsif agent
           query = query.or(
             events_table[:creator_id].eq(agent.id)
           )