[Task builder] Save notifications recipient entry when 'no recipient is selected.
When editing tasks in the Task builder;
- Admin should be able to select and save a task notification recipient entry when no 'Recipient' is selected.
- Admin should be able to delete task notification recipient and the notification entry should still be saved.
- Admin should be able to add multiple notification entries without having selected a Recipient or Notification template. - so don't disable the 'Add new notification' action when a no recipient is selected.