title: Create multiple subcategories and assign them to supercategory in impex file
body: <p>I'm trying to create multiple subcategories to a supercategory with one line in impex file.
  Something like this:</p>
  
  <pre><code>INSERT_UPDATE Category;code[unique=true];categories(code, $productCV);$productCV
  ;001;001001,001002,001003
  </code></pre>
  
  <p>The code above is not working.
  I want 001 to be a supercategory for 001001, 001002, 001003</p>
  
  <p>I can do this in 3 lines for example:</p>
  
  <pre><code>INSERT_UPDATE Category;code[unique=true];$supercategories[default='catalog'];$productCV
  ;001001;001
  ;001002;001
  ;001003;001
  </code></pre>
  
  <p>Just wondering is it possible to do it with one line? Couldn't find a qualifier to do this.</p>
  
  <p>Thanks!</p>