title: EF Core and Collection ordering by specified column: move up and down
body: <p>What is a best way to implement ordering in collection?
  Need to support operations like <code>move up</code> and <code>move down</code>.</p>
  
  <pre><code>public class Item
  {
      public int Id { get; set; }
      public string Name { get; set; }
      public int Priority { get; set; }
      public List&lt;Item&gt; Items { get; set; }
  }
  </code></pre>