Move Mobilizon.Events.Activity to Mobilizon.Service.ActivityPub.Activity

It's only used for ActivityPub stuff, nothing DB related.

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

lib/service/activity_pub/activity.ex

@@ -0,0 +1,21 @@
+defmodule Mobilizon.Service.ActivityPub.Activity do
+  @moduledoc """
+  Represents an activity.
+  """
+
+  @type t :: %__MODULE__{
+          data: String.t(),
+          local: boolean,
+          actor: Actor.t(),
+          recipients: [String.t()]
+          # notifications: [???]
+        }
+
+  defstruct [
+    :data,
+    :local,
+    :actor,
+    :recipients
+    # :notifications
+  ]
+end