fix(activitypub): compact ical:status in activitystream data

Was kept for no other reason than disambiguation with https://schema.org/status, but no need if we
specify the correct alias in the context.

Keeps a fallback for older versions compatibility

Closes #1378

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

lib/federation/activity_pub/utils.ex

@@ -165,6 +165,10 @@ defmodule Mobilizon.Federation.ActivityPub.Utils do
           "todos" => %{
             "@id" => "mz:todos",
             "@type" => "@id"
+          },
+          "status" => %{
+            "@id" => "ical:status",
+            "@type" => "ical:status"
           }
         }
       ]