Add simple tests for Scintilla annotations to the stc sample.

Show how add, remove and clear annotations and also how to update the text
width when long annotations are added.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@73463 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

samples/stc/edit.h

@@ -91,6 +91,11 @@ public:
     void OnSetReadOnly (wxCommandEvent &event);
     void OnWrapmodeOn (wxCommandEvent &event);
     void OnUseCharset (wxCommandEvent &event);
+    // annotations
+    void OnAnnotationAdd(wxCommandEvent& event);
+    void OnAnnotationRemove(wxCommandEvent& event);
+    void OnAnnotationClear(wxCommandEvent& event);
+    void OnAnnotationStyle(wxCommandEvent& event);
     //! extra
     void OnChangeCase (wxCommandEvent &event);
     void OnConvertEOL (wxCommandEvent &event);