Add wxVersionInfo and functions returning it for 3rd party libraries.

Add simple wxVersionInfo class holding the version information.

Also add GetLibraryVersionInfo() static method to wx{JPEG,PNG,TIFF}Handler,
wxStyledTextCtrl and wxXmlDocument classes and wxGetZlibVersionInfo() and
wxGetLibraryVersionInfo() global functions using it.

Closes #12690.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@66259 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/stc/stc.h

@@ -4240,6 +4240,8 @@ public:
         return wxTextAreaBase::HitTest(pt, col, row);
     }
 
+    static wxVersionInfo GetLibraryVersionInfo();
+
 protected:
     virtual wxString DoGetValue() const { return GetText(); }
     virtual wxWindow *GetEditableWindow() { return this; }