Fix handling of accelerators in wxOSX

Check accelerator tables when handling wxEVT_CHAR_HOOK, not
wxEVT_KEY_DOWN, as we don't get the latter at all for some events, e.g.
Cmd-Alt-1 doesn't generate wxEVT_KEY_DOWN (which looks like another bug)
but does generate wxEVT_CHAR_HOOK.

Closes #13937.

src/osx/window_osx.cpp

@@ -2573,7 +2573,7 @@ bool wxWindowMac::OSXHandleKeyEvent( wxKeyEvent& event )
     // moved the ordinary key event sending AFTER the accel evaluation
 
 #if wxUSE_ACCEL
-    if (event.GetEventType() == wxEVT_KEY_DOWN)
+    if (event.GetEventType() == wxEVT_CHAR_HOOK)
     {
         wxWindow *ancestor = this;
         while (ancestor)