Clean up wxMSW tooltip window on library shutdown

Not doing this prevented the tooltips from working correctly if the library
was shut down and reinitialized again, so add a module ensuring this is done.

Closes #17360.

include/wx/msw/tooltip.h

@@ -74,6 +74,9 @@ public:
     static void UpdateVisibility();
 
 private:
+    // This module calls our DeleteToolTipCtrl().
+    friend class wxToolTipModule;
+
     // Adds a window other than our main m_window to this tooltip.
     void DoAddHWND(WXHWND hWnd);
 
@@ -92,6 +95,9 @@ private:
     // create the tooltip ctrl if it doesn't exist yet and return its HWND
     static WXHWND GetToolTipCtrl();
 
+    // to be used in wxModule for deleting tooltip ctrl window when exiting mainloop
+    static void DeleteToolTipCtrl();
+
     // new tooltip maximum width, defaults to min(display width, 400)
     static int ms_maxWidth;