Allow assigning users to reports

Signed-off-by: nicole mikołajczyk <git@mkljczk.pl>

priv/repo/migrations/20220225164000_add_activity_assigned_account_index.exs

@@ -0,0 +1,11 @@
+defmodule Pleroma.Repo.Migrations.AddActivityAssignedAccountIndex do
+  use Ecto.Migration
+
+  def change do
+    create_if_not_exists(
+      index(:activities, ["(data->>'assigned_account')"],
+        name: :activities_assigned_account_index
+      )
+    )
+  end
+end