Introduce the group activity section

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

lib/service/workers/activity_builder.ex

@@ -0,0 +1,22 @@
+defmodule Mobilizon.Service.Workers.ActivityBuilder do
+  @moduledoc """
+  Worker to insert activity items in users feeds
+  """
+
+  alias Mobilizon.Activities
+  alias Mobilizon.Activities.Activity
+
+  use Mobilizon.Service.Workers.Helper, queue: "activity"
+
+  @impl Oban.Worker
+  def perform(%Job{args: args}) do
+    with {"build_activity", args} <- Map.pop(args, "op") do
+      build_activity(args)
+    end
+  end
+
+  @spec build_activity(map()) :: {:ok, Activity.t()}
+  def build_activity(args) do
+    Activities.create_activity(args)
+  end
+end