#1036 removing unused references

Author: IbraheemOsama

Microsoft.Toolkit.Uwp.UI.Controls/GridSplitter/GridSplitter.Events.cs

@@ -45,7 +45,7 @@ private void GridSplitter_Loaded(object sender, RoutedEventArgs e)
 
             Element = gripper;
 
-            gripper.KeyDown += Gripper_KeyDown;
+            KeyDown += Gripper_KeyDown;
 
             var hoverWrapper = new GripperHoverWrapper(
                 CursorBehavior == SplitterCursorBehavior.ChangeOnSplitterHover

Microsoft.Toolkit.Uwp.UI.Controls/GridSplitter/GridSplitterGripper.cs

@@ -10,7 +10,6 @@
 // THE CODE OR THE USE OR OTHER DEALINGS IN THE CODE.
 // ******************************************************************
 
-using System;
 using Windows.UI.Xaml;
 using Windows.UI.Xaml.Controls;
 using Windows.UI.Xaml.Media;
@@ -47,8 +46,8 @@ internal GridSplitterGripper(GridSplitter.GridResizeDirection gridSplitterDirect
             ResizeDirection = gridSplitterDirection;
             HorizontalContentAlignment = HorizontalAlignment.Stretch;
             VerticalContentAlignment = VerticalAlignment.Stretch;
-            IsTabStop = true;
-            UseSystemFocusVisuals = true;
+            //IsTabStop = true;
+            //UseSystemFocusVisuals = true;
         }
 
         internal GridSplitterGripper(