Use gtk_list_store_insert_with_values() to set entry at same time item is inserted.
This should ensure that the entry is always valid, removing the need for r74315.
Also simplify DoInsertItems() by using DoInsertItemsInLoop().


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74317 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775