Restore the use of wxListCtrl in report view in wxListbook.

This reverts r71965 for wxMSW as the list mode there doesn't work correctly if
there are sufficiently many items: the native control insists on laying them
out in multiple columns which is inappropriate for wxListbook, so use report
mode for horizontal wxListbooks. Do use the list mode in the vertical case as
we do want to have multiple columns -- and not rows -- then.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72340 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/listbook.h

@@ -88,6 +88,9 @@ protected:
     wxBookCtrlEvent* CreatePageChangingEvent() const;
     void MakeChangedEvent(wxBookCtrlEvent &event);
 
+    // Get the correct wxListCtrl flags to use depending on our own flags.
+    long GetListCtrlFlags() const;
+
     // event handlers
     void OnListSelected(wxListEvent& event);
     void OnSize(wxSizeEvent& event);