title: Trying to orderby with case when clause for MultiDocumentQuery?
body: <p>I am trying to get all my pagetypes from kentico, but I would like to order them by all the page types that starts with the letter "F", first and then the other pages alphabetically. </p>
  
  <p>What I am trying is:</p>
  
  <p><code>1) MultiDocumentQuery docQuery = DocumentHelper.GetDocuments().Type("forms").OnSite(SiteContext.CurrentSiteID).Published(); 
  2) docQuery.OrderBy("FormName");</code></p>
  
  <p>But what I need is to order em using something like this (SQL):</p>
  
  <p><code>SELECT FormName
  FROM Forms
  order by
    case when FormName like 'C%' then 0 else 1 end,
    FormName</code></p>
  
  <p>What I cant do is to translate the <code>case when</code> properly to c#, and implement it to docQuery.
  So the result should be for example,:</p>
  
  <ol>
  <li>Form1  </li>
  <li>Form2</li>
  <li>Form3</li>
  <li>A...</li>
  <li>B...</li>
  </ol>