title: Sitecore file upload event
body: <p>I need to itercept event when user uploads file into file drop area.</p>
  
  <p>In this event I should have access to item that has file drop area and file that has been uploaded.</p>
  
  <p>I tried item:saved and uiUpload processor but they don't provide enough information.</p>
  
  <p>What I need is:</p>
  
  <ul>
  <li>File drop area field ID</li>
  <li>Upadete item</li>
  <li>Uploaded file name</li>
  </ul>
  
  <p>Do sitecore have event for such kind of user action with all required information? </p>