macOS: Check subview position in ComponentPeer::toFront() and toBehind() before re-ordering subviews for shared windows

This commit also removes the subview from its superview's subview array before re-ordering as the macOS docs don't make any guarantees about what happens when adding a subview that is already contained in the array.

modules/juce_gui_basics/native/juce_mac_NSViewComponentPeer.mm

@@ -479,9 +479,22 @@ public:
     void toFront (bool makeActiveWindow) override
     {
         if (isSharedWindow)
-            [[view superview] addSubview: view
-                              positioned: NSWindowAbove
-                              relativeTo: nil];
+        {
+            NSView* superview = [view superview];
+            NSMutableArray* subviews = [NSMutableArray arrayWithArray: [superview subviews]];
+
+            const auto isFrontmost = [[subviews lastObject] isEqual: view];
+
+            if (! isFrontmost)
+            {
+                [view retain];
+                [subviews removeObject: view];
+                [subviews addObject: view];
+
+                [superview setSubviews: subviews];
+                [view release];
+            }
+        }
 
         if (window != nil && component.isVisible())
         {
@@ -508,9 +521,26 @@ public:
         {
             if (isSharedWindow)
             {
-                [[view superview] addSubview: view
-                                  positioned: NSWindowBelow
-                                  relativeTo: otherPeer->view];
+                NSView* superview = [view superview];
+                NSMutableArray* subviews = [NSMutableArray arrayWithArray: [superview subviews]];
+
+                const auto otherViewIndex = [subviews indexOfObject: otherPeer->view];
+
+                if (otherViewIndex == NSNotFound)
+                    return;
+
+                const auto isBehind = [subviews indexOfObject: view] < otherViewIndex;
+
+                if (! isBehind)
+                {
+                    [view retain];
+                    [subviews removeObject: view];
+                    [subviews insertObject: view
+                                   atIndex: otherViewIndex];
+
+                    [superview setSubviews: subviews];
+                    [view release];
+                }
             }
             else if (component.isVisible())
             {