UI: Fade all non-ID children if parent is hidden in outliner

Part of !120397.
For non-id tree elements, call `element_should_draw_faded` and get the
fade status of their parent. For example, this will fix the fading of
modifier, actions, bones, etc. in outliner.

Pull Request: https://projects.blender.org/blender/blender/pulls/120813

source/blender/editors/space_outliner/outliner_draw.cc

@@ -3326,6 +3326,11 @@ static bool element_should_draw_faded(const TreeViewContext *tvc,
           tree_element_cast<TreeElementGreasePencilNode>(te)->node();
       return !node.is_visible();
     }
+    default: {
+      if (te->parent) {
+        return element_should_draw_faded(tvc, te->parent, te->parent->store_elem);
+      }
+    }
   }
 
   if (te->flag & TE_CHILD_NOT_IN_COLLECTION) {