Aligning Kill Process with End Task naming (#40263)

- Renaming "Kill process" to "End task" to align with Windows.
- Updating End task and Close window icons to align with End Task in
Windows.

---------

Co-authored-by: Niels Laute <niels.laute@live.nl>

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.WindowWalker/Commands/CloseWindowCommand.cs

@@ -20,7 +20,7 @@ internal sealed partial class CloseWindowCommand : InvokableCommand
 
     public CloseWindowCommand(Window window)
     {
-        Icon = new IconInfo("\xE8BB");
+        Icon = new IconInfo("\uE894");
         Name = $"{Resources.windowwalker_Close}";
         _window = window;
     }