Add wxTopLevelWindow::SetContentProtection()

This method allows to exclude a top level window from screen captures.
Windows 7 or newer is required and any macOS version is supported.
Other platforms are not implemented and will return false.

The display example has been extended to demo this ability.

Closes #22066.

include/wx/osx/core/private.h

@@ -76,6 +76,7 @@ WXDLLIMPEXP_BASE CFURLRef wxOSXCreateURLFromFileSystemPath( const wxString& path
 
 #include "wx/bmpbndl.h"
 #include "wx/window.h"
+#include "wx/toplevel.h"
 
 class wxTextProofOptions;
 
@@ -965,6 +966,9 @@ public :
 
     virtual bool ShowFullScreen(bool show, long style)= 0;
 
+    virtual wxContentProtection GetContentProtection() const = 0;
+    virtual bool SetContentProtection(wxContentProtection contentProtection) = 0;
+
     virtual void RequestUserAttention(int flags) = 0;
 
     virtual void ScreenToWindow( int *x, int *y ) = 0;