Remove activateAppropriateChild logic.

It was causing both parent and child windows to think they were the key window at the same time and it's not really needed anymore since the implementation of real child windows as far as I can see.

native/Avalonia.Native/src/OSX/window.mm

@@ -2055,22 +2055,6 @@ NSArray* AllLoopModes = [NSArray arrayWithObjects: NSDefaultRunLoopMode, NSEvent
     return _canBecomeKeyAndMain;
 }
 
--(bool) activateAppropriateChild: (bool)activating
-{
-    for(NSWindow* uch in [self childWindows])
-    {
-        auto ch = objc_cast<AvnWindow>(uch);
-        if(ch == nil)
-            continue;
-        [ch activateAppropriateChild:false];
-        return FALSE;
-    }
-    
-    if(!activating)
-        [self makeKeyAndOrderFront:self];
-    return TRUE;
-}
-
 -(bool)shouldTryToHandleEvents
 {
     return _isEnabled;
@@ -2081,26 +2065,15 @@ NSArray* AllLoopModes = [NSArray arrayWithObjects: NSDefaultRunLoopMode, NSEvent
     _isEnabled = enable;
 }
 
--(void)makeKeyWindow
-{
-    if([self activateAppropriateChild: true])
-    {
-        [super makeKeyWindow];
-    }
-}
-
 -(void)becomeKeyWindow
 {
     [self showWindowMenuWithAppMenu];
     
-    if([self activateAppropriateChild: true])
+    if(_parent != nullptr)
     {
-        if(_parent != nullptr)
+        _parent->BaseEvents->Activated();
-        {
-            _parent->BaseEvents->Activated();
-        }
     }
-    
+
     [super becomeKeyWindow];
 }
 
@@ -2110,7 +2083,6 @@ NSArray* AllLoopModes = [NSArray arrayWithObjects: NSDefaultRunLoopMode, NSEvent
     if(parent != nil)
     {
         [parent removeChildWindow:self];
-        [parent activateAppropriateChild: false];
     }
 }