title: How to remove "Custom" filter from TcxGrid column filters?
body: <p>I have a TcxGrid with some columns and data. Columns allow filtering:</p>
  
  <p><a href="https://i.stack.imgur.com/gFqME.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/gFqME.png" alt="enter image description here"></a></p>
  
  <p>I want to remove the "Custom" option from the drop-down filter, but leave all the rest ([All] and auto-suggested). How do I do this?</p>