title: DevExtreme Autocomplete does not filter
body: <p>I'm using DevExtreme and have a problem with Autocomplete widget.</p>
  
  <p>This is my code to create autocomplete</p>
  
  <pre><code>@(Html.DevExtreme().AutocompleteFor(m =&gt; m.CityName)
      .ID("edCity")
      .Placeholder(Html.DisplayNameFor(m =&gt; m.CityName).ToString())
      .MinSearchLength(3)
      .SearchTimeout(500)
      .ValueExpr("Name")
      .DataSource(d =&gt; d.WebApi().Controller("LNAX").LoadAction("Cities").Key("Name").LoadParams(new { id = 5 }))
  )
  </code></pre>
  
  <p>This is the City class</p>
  
  <pre><code>public class City
  {
      public int Id { get; set; }
      public string Name { get; set; }
  }
  </code></pre>
  
  <p>When I start typing in the exit box. it show all the Cities in the drop-down list. My expectation is show a filtered list beased on what I have typed in.</p>
  
  <p>What is missing in configuring the widget?</p>