Fix #142285: 3D cursor placement ignores unselectable objects

This was caused by 3dfec1ff73
which introduce the new behavior. This was to fix workflows
using a lot of semi-transparent objects which made nagivation
difficult.

This patch first roll back to the previous behavior: The
unselectable object will affect depth-aware operators.

This patch introduces a new visibility property to remove
the influence of objects in all depth picking operations
and selection operations. However the object is still
selectable through non-drawing selection operators
(e.g. select by material) and through the outliner.
This is to adress the aforementionned navigation issues.

Pull Request: https://projects.blender.org/blender/blender/pulls/146706

source/blender/draw/engines/overlay/overlay_instance.cc

@@ -1089,6 +1089,10 @@ bool Instance::object_needs_prepass(const ObjectRef &ob_ref, bool in_paint_mode)
   }
 
   if (resources.is_selection() || state.is_depth_only_drawing) {
+    if (ob_ref.object->visibility_flag & OB_HIDE_SURFACE_PICK) {
+      /* Special flag to avoid surfaces to contribute to depth picking and selection. */
+      return false;
+    }
     /* Selection and depth picking always need a prepass.
      * Note that depth writing and depth test might be disable for certain selection mode. */
     return true;