cocoa: allow default handling of Cmd-` for cycling windows

Closes PR 11499
 but it's not clear that this is the right fix for all users

original commit: 355cf25b5f84f72dacc2a729ae6d156d203b3998

collects/mred/private/wx/cocoa/menu-bar.rkt

@@ -46,7 +46,12 @@
                (tell #:type _BOOL the-apple-menu performKeyEquivalent: evt))
           ;; Explicity send the event to the keyWindow:
           (and
+           ;; Don't go into an infinite loop:
            (not (recurring-for-command))
+           ;; Don't handle Cmd-` for cycling through windows:
+           ;; [Is this right for all locales?]
+           (not (equal? "`" (tell #:type _NSString evt characters)))
+           ;; Otherwise, try to dispatch to the first respnder:
            (let ([w (tell app keyWindow)])
              (and w
                   (let ([r (tell w firstResponder)])