macosx: make sure that the http interface (and other clients) can toggle the...

macosx: make sure that the http interface (and other clients) can toggle the fullscreen mode when using VLC's fullscreen implementation (close #6009)
(cherry picked from commit 2a2bb7af)

modules/gui/macosx/misc.m

@@ -31,6 +31,7 @@
 #import "misc.h"
 #import "playlist.h"
 #import "controls.h"
+#import "CoreInteraction.h"
 #import <vlc_url.h>
 
 /*****************************************************************************
@@ -369,6 +370,11 @@ static NSMutableArray *blackoutWindows = NULL;
     return b_isFullscreen;
 }
 
+- (IBAction)fullscreen:(id)sender
+{
+    [[VLCCoreInteraction sharedInstance] toggleFullscreen];
+}
+
 @end
 
 /*****************************************************************************