ux: add Ctrl+Insert copy shortcut in diff view (#2657)

Author: bartizan

src/Views/TextDiffView.axaml.cs

@@ -662,7 +662,7 @@ private async void OnTextAreaKeyDown(object sender, KeyEventArgs e)
         {
             if (e.KeyModifiers.Equals(OperatingSystem.IsMacOS() ? KeyModifiers.Meta : KeyModifiers.Control))
             {
-                if (e.Key == Key.C)
+                if (e.Key is Key.C or Key.Insert)
                 {
                     e.Handled = true;