Reset current category marker if deleted wxPG property is a category property.

If deleted category or its sub-category is a current category then reset current category marker.

See #16617.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@78112 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/propgrid/propgridpagestate.h

@@ -714,6 +714,10 @@ protected:
      */
     void DoInvalidateChildrenNames(wxPGProperty* p, bool recursive);
 
+    /** Check if property contains given sub-category */
+    bool IsChildCategory(wxPGProperty* p,
+                         wxPropertyCategory* cat, bool recursive);
+
     /** If visible, then this is pointer to wxPropertyGrid.
         This shall *never* be NULL to indicate that this state is not visible.
     */