Restore propagation of EVT_SEARCHCTRL_CANCEL_BTN events to the parent.

This was broken by r72581, add event.Skip() call to the handler for this event
added there.

Also add a handler for this event to the corresponding page of the widgets
sample to be able to test this.

Closes #14799.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72915 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

samples/widgets/searchctrl.cpp

@@ -85,6 +85,7 @@ protected:
     void OnToggleSearchMenu(wxCommandEvent&);
 
     void OnSearch(wxCommandEvent& event);
+    void OnSearchCancel(wxCommandEvent& event);
 
     wxMenu* CreateTestMenu();
 
@@ -112,6 +113,7 @@ BEGIN_EVENT_TABLE(SearchCtrlWidgetsPage, WidgetsPage)
     EVT_CHECKBOX(ID_MENU_CB, SearchCtrlWidgetsPage::OnToggleSearchMenu)
 
     EVT_SEARCHCTRL_SEARCH_BTN(wxID_ANY, SearchCtrlWidgetsPage::OnSearch)
+    EVT_SEARCHCTRL_CANCEL_BTN(wxID_ANY, SearchCtrlWidgetsPage::OnSearchCancel)
 END_EVENT_TABLE()
 
 // ============================================================================
@@ -231,4 +233,11 @@ void SearchCtrlWidgetsPage::OnSearch(wxCommandEvent& event)
     wxLogMessage("Search button: search for \"%s\".", event.GetString());
 }
 
+void SearchCtrlWidgetsPage::OnSearchCancel(wxCommandEvent& event)
+{
+    wxLogMessage("Cancel button pressed.");
+
+    event.Skip();
+}
+
 #endif  //  wxUSE_SEARCHCTRL