title: Virtual String Tree - Display subnode when parent node is hidden
body: <p><strong>Is there a way to show subnode if the parent node is hidden in the Virtual String Tree ?</strong><br><br>
  I have some tasks in the tree structure and I wish to display only tasks which belongs to the current user as the list, but from all levels.
  What I've done is the function to display a list, which hides tree buttons, tree lines, sets the fixed indent and enable toShowHiddenNodes option. Then in this function I iterate through the whole tree (all levels) and hide nodes which doesn't belong to the current user <strong>IsVisible[Node] := False</strong> and show those which belongs him <strong>IsVisible[Node] := True</strong>, but the subnodes which should be displayed are invisible when their parent is hidden.</p>
  
  <p>VT.TreeOptions.PaintOptions<br>
  - toShowButtons<br>
  - toShowTreeLines<br>
  + toFixedIndent<br>
  + toShowHiddenNodes</p>
  
  <p><img src="https://i.stack.imgur.com/FmlE5.jpg" alt="alt text"></p>