Added service for model management for machine learning extension (#1138)

* Added service for model management for ml extension

src/Microsoft.SqlTools.ServiceLayer/ModelManagement/Contracts/ModelRequestBase.cs

@@ -0,0 +1,36 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using Microsoft.SqlTools.ServiceLayer.Utility;
+
+namespace Microsoft.SqlTools.ServiceLayer.ModelManagement.Contracts
+{
+    public class ModelRequestBase
+    {
+        /// <summary>
+        /// Models database name
+        /// </summary>
+        public string DatabaseName { get; set; }
+
+        /// <summary>
+        /// The schema for model table
+        /// </summary>
+        public string SchemaName { get; set; }
+
+        /// <summary>
+        /// Models table name
+        /// </summary>
+        public string TableName { get; set; }
+
+        /// <summary>
+        /// Connection uri
+        /// </summary>
+        public string OwnerUri { get; set; }
+    }
+
+    public class ModelResponseBase
+    {
+    }
+}