Replace 3 copies of wxListCtrl mode tests with a single one in wxListCtrlBase.

Move InReportView() and IsVirtual() into the base class as they were the same
in all the implementations.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@70281 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/listbase.h

@@ -383,6 +383,10 @@ class WXDLLIMPEXP_CORE wxListCtrlBase : public wxControl
 {
 public:
     wxListCtrlBase() { }
+
+    // Convenient functions for testing the list control mode:
+    bool InReportView() const { return HasFlag(wxLC_REPORT); }
+    bool IsVirtual() const { return HasFlag(wxLC_VIRTUAL); }
 };
 
 // ----------------------------------------------------------------------------