[WASM] Fix cursors in macOS, fix default cursor set logic

src/Web/Avalonia.Web.Blazor/AvaloniaView.razor.cs

@@ -259,7 +259,11 @@ namespace Avalonia.Web.Blazor
 
                     _inputHelper.Hide();
                     _canvasHelper.SetCursor("default");
-                    _topLevelImpl.SetCssCursor = _canvasHelper.SetCursor;
+                    _topLevelImpl.SetCssCursor = x =>
+                    {
+                        _inputHelper.SetCursor(x);//macOS
+                        _canvasHelper.SetCursor(x);//windows
+                    };
 
                     Console.WriteLine("starting html canvas setup");
                     _interop = await SKHtmlCanvasInterop.ImportAsync(Js, _htmlCanvas, OnRenderFrame);

src/Web/Avalonia.Web.Blazor/RazorViewTopLevelImpl.cs

@@ -127,15 +127,11 @@ namespace Avalonia.Web.Blazor
 
         public void SetCursor(ICursorImpl cursor)
         {
-            var cur = cursor as CssCursor;
-            var val = CssCursor.Default;
-            if (cur != null && cur.Value != null)
-            {
-                val = cur.Value;
-            }
+            var val = (cursor as CssCursor)?.Value ?? CssCursor.Default;
             if (_currentCursor != val)
             {
                 SetCssCursor?.Invoke(val);
+                _currentCursor = val;
             }
         }