Implement wxDirDialog:: and wxFileDialog::Create() in wxGTK.

Simply move the code from non-default constructor to Create(). This allows to
create the dialogs using 2-step creation if necessary.

Closes #14069.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@70898 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gtk/filedlg.h

@@ -30,6 +30,15 @@ public:
                  const wxPoint& pos = wxDefaultPosition,
                  const wxSize& sz = wxDefaultSize,
                  const wxString& name = wxFileDialogNameStr);
+    bool Create(wxWindow *parent,
+                 const wxString& message = wxFileSelectorPromptStr,
+                 const wxString& defaultDir = wxEmptyString,
+                 const wxString& defaultFile = wxEmptyString,
+                 const wxString& wildCard = wxFileSelectorDefaultWildcardStr,
+                 long style = wxFD_DEFAULT_STYLE,
+                 const wxPoint& pos = wxDefaultPosition,
+                 const wxSize& sz = wxDefaultSize,
+                 const wxString& name = wxFileDialogNameStr);
     virtual ~wxFileDialog();
 
     virtual wxString GetPath() const;