Add a dropdown on participate menu, disallow listing participations

Now requires quering the person endpoint to know if an actor
participates in an event, organizers can make authenticated requests to
event { participants { } } to see the pending / approved participants.

Also closes #174

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

lib/mobilizon_web/schema/actors/person.ex

@@ -56,8 +56,11 @@ defmodule MobilizonWeb.Schema.Actors.PersonType do
     )
 
     @desc "The list of events this person goes to"
-    field :going_to_events, list_of(:event) do
-      resolve(&Person.person_going_to_events/3)
+    field(:participations, list_of(:participant),
+      description: "The list of events this person goes to"
+    ) do
+      arg(:event_id, :id)
+      resolve(&Person.person_participations/3)
     end
   end