activity_draft: Add source field

lib/pleroma/web/common_api/activity_draft.ex

@@ -186,6 +186,7 @@ defp object(draft) do
         draft.poll
       )
       |> Map.put("emoji", emoji)
+      |> Map.put("source", draft.status)
 
     %__MODULE__{draft | object: object}
   end

test/web/common_api/common_api_test.exs

@@ -445,6 +445,7 @@ test "it filters out obviously bad tags when accepting a post as HTML" do
       object = Object.normalize(activity)
 
       assert object.data["content"] == "<p><b>2hu</b></p>alert(&#39;xss&#39;)"
+      assert object.data["source"] == post
     end
 
     test "it filters out obviously bad tags when accepting a post as Markdown" do
@@ -461,6 +462,7 @@ test "it filters out obviously bad tags when accepting a post as Markdown" do
       object = Object.normalize(activity)
 
       assert object.data["content"] == "<p><b>2hu</b></p>alert(&#39;xss&#39;)"
+      assert object.data["source"] == post
     end
 
     test "it does not allow replies to direct messages that are not direct messages themselves" do