Add missing default constructor of wxFileDialog in wxMSW

This ctor exists in the other ports and there is no reason for it not to
exist in wxMSW too.

Closes #24113.

include/wx/msw/filedlg.h

@@ -19,6 +19,7 @@ class wxFileDialogMSWData;
 class WXDLLIMPEXP_CORE wxFileDialog: public wxFileDialogBase
 {
 public:
+    wxFileDialog() = default;
     wxFileDialog(wxWindow *parent,
                  const wxString& message = wxASCII_STR(wxFileSelectorPromptStr),
                  const wxString& defaultDir = wxEmptyString,