Stop CommandException from printing a stack

This was a bug due to copy-paste of CommandException. Now the cases where
we intentionally fail will no longer have a call stack.

src/Tye.Core/CommandException.cs

@@ -6,7 +6,7 @@ using System;
 
 namespace Tye
 {
-    internal class CommandException : Exception
+    public class CommandException : Exception
     {
         public CommandException(string message)
             : base(message)

src/tye/CommandException.cs

@@ -1,21 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-using System;
-
-namespace Tye
-{
-    internal class CommandException : Exception
-    {
-        public CommandException(string message)
-            : base(message)
-        {
-        }
-
-        public CommandException(string message, Exception innerException)
-            : base(message, innerException)
-        {
-        }
-    }
-}