Added service class for machine learning services operations (#906)

* Added service class for server configurations and language extension

src/Microsoft.SqlTools.ServiceLayer/ServerConfigurations/ServerConfigException.cs

@@ -0,0 +1,27 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using System;
+
+namespace Microsoft.SqlTools.ServiceLayer.ServerConfigurations
+{
+    /// <summary>
+    /// Exception raised from machine learning services operations
+    /// </summary>
+    public class ServerConfigException : Exception
+    {
+        internal ServerConfigException() : base()
+        {
+        }
+
+        internal ServerConfigException(string m) : base(m)
+        {
+        }
+
+        internal ServerConfigException(string m, Exception innerException) : base(m, innerException)
+        {
+        }
+    }
+}