fixed binding issue of edit element on Uno

Author: w-ahmad

src/Columns/TableViewNumberColumn.cs

@@ -38,7 +38,9 @@ public override FrameworkElement GenerateEditingElement(TableViewCell cell, obje
     {
         var numberBox = new NumberBox();
         numberBox.SetBinding(NumberBox.ValueProperty, Binding);
-
+#if !WINDOWS
+        numberBox.DataContext = dataItem;
+#endif
         return numberBox;
     }
 }

src/Columns/TableViewTextColumn.cs

@@ -36,7 +36,9 @@ public override FrameworkElement GenerateEditingElement(TableViewCell cell, obje
     {
         var textBox = new TextBox();
         textBox.SetBinding(TextBox.TextProperty, Binding);
-
+#if !WINDOWS
+        textBox.DataContext = dataItem;
+#endif
         return textBox;
     }
 }