ObjectValidators: Add basic UpdateValidator.

lib/pleroma/web/activity_pub/builder.ex

@@ -123,6 +123,21 @@ defmodule Pleroma.Web.ActivityPub.Builder do
     end
   end
 
+  # Retricted to user updates for now, always public
+  @spec update(User.t(), Object.t()) :: {:ok, map(), keyword()}
+  def update(actor, object) do
+    to = [Pleroma.Constants.as_public(), actor.follower_address]
+
+    {:ok,
+     %{
+       "id" => Utils.generate_activity_id(),
+       "type" => "Update",
+       "actor" => actor.ap_id,
+       "object" => object,
+       "to" => to
+     }, []}
+  end
+
   @spec announce(User.t(), Object.t(), keyword()) :: {:ok, map(), keyword()}
   def announce(actor, object, options \\ []) do
     public? = Keyword.get(options, :public, false)