Avoid deprecated input API in win32 backend

src/Windows/Avalonia.Win32/Input/WindowsMouseDevice.cs

@@ -8,15 +8,28 @@ namespace Avalonia.Win32.Input
 {
     class WindowsMouseDevice : MouseDevice
     {
-        public WindowsMouseDevice() : base(new WindowsMousePointer())
+        private readonly IPointer _pointer;
+        public WindowsMouseDevice() : base(WindowsMousePointer.CreatePointer(out var pointer))
         {
-            
+            _pointer = pointer;
+        }
+
+        // Normally user should use IPointer.Capture instead of MouseDevice.Capture,
+        // But on Windows we need to handle WM_MOUSE capture manually without having access to the Pointer. 
+        internal void Capture(IInputElement control)
+        {
+            _pointer.Capture(control);
         }
         
-        class WindowsMousePointer : Pointer
+        internal class WindowsMousePointer : Pointer
         {
-            public WindowsMousePointer() : base(Pointer.GetNextFreeId(),PointerType.Mouse, true)
+            private WindowsMousePointer() : base(Pointer.GetNextFreeId(),PointerType.Mouse, true)
+            {
+            }
+            
+            public static WindowsMousePointer CreatePointer(out WindowsMousePointer pointer)
             {
+                return pointer = new WindowsMousePointer();
             }
 
             protected override void PlatformCapture(IInputElement element)

src/Windows/Avalonia.Win32/WindowImpl.cs

@@ -72,7 +72,7 @@ namespace Avalonia.Win32
 
         private const WindowStyles WindowStateMask = (WindowStyles.WS_MAXIMIZE | WindowStyles.WS_MINIMIZE);
         private readonly TouchDevice _touchDevice;
-        private readonly MouseDevice _mouseDevice;
+        private readonly WindowsMouseDevice _mouseDevice;
         private readonly PenDevice _penDevice;
         private readonly ManagedDeferredRendererLock _rendererLock;
         private readonly FramebufferManager _framebuffer;
@@ -689,10 +689,9 @@ namespace Avalonia.Win32
 
         public void BeginMoveDrag(PointerPressedEventArgs e)
         {
-            _mouseDevice.Capture(null);
+            e.Pointer.Capture(null);
             DefWindowProc(_hwnd, (int)WindowsMessage.WM_NCLBUTTONDOWN,
                 new IntPtr((int)HitTestValues.HTCAPTION), IntPtr.Zero);
-            e.Pointer.Capture(null);
         }
 
         public void BeginResizeDrag(WindowEdge edge, PointerPressedEventArgs e)
@@ -702,7 +701,7 @@ namespace Avalonia.Win32
 #if USE_MANAGED_DRAG
                 _managedDrag.BeginResizeDrag(edge, ScreenToClient(MouseDevice.Position.ToPoint(_scaling)));
 #else
-                _mouseDevice.Capture(null);
+                e.Pointer.Capture(null);
                 DefWindowProc(_hwnd, (int)WindowsMessage.WM_NCLBUTTONDOWN,
                     new IntPtr((int)s_edgeLookup[edge]), IntPtr.Zero);
 #endif