Implement incremental search in wxGenericListCtrl.

Mostly copy wxGenericTreeCtrl incremental search implementation to
wxGenericListCtrl (unfortunately there is no simple way to reuse this code
currently), including the recently added EnableBellOnNoMatch() method.

Update the sample to test it, the key event handling in it had to be modified
to allow it.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72639 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/generic/listctrl.h

@@ -144,6 +144,8 @@ public:
     void RefreshItem(long item);
     void RefreshItems(long itemFrom, long itemTo);
 
+    virtual void EnableBellOnNoMatch(bool on);
+
 #if WXWIN_COMPATIBILITY_2_6
     // obsolete, don't use
     wxDEPRECATED( int GetItemSpacing( bool isSmall ) const );