set issupportedVersion flag (#1255)

src/Microsoft.SqlTools.ServiceLayer/Connection/ConnectionService.cs

@@ -480,6 +480,8 @@ namespace Microsoft.SqlTools.ServiceLayer.Connection
                 connectionInfo.IsSqlDb = serverInfo.EngineEditionId == (int)DatabaseEngineEdition.SqlDatabase;
                 connectionInfo.IsSqlDW = (serverInfo.EngineEditionId == (int)DatabaseEngineEdition.SqlDataWarehouse);
                 connectionInfo.EngineEdition = (DatabaseEngineEdition)serverInfo.EngineEditionId;
+                // Azure Data Studio supports SQL Server 2014 and later releases.
+                response.IsSupportedVersion = serverInfo.IsCloud || serverInfo.ServerMajorVersion >= 12;
             }
             catch (Exception ex)
             {

src/Microsoft.SqlTools.ServiceLayer/Connection/Contracts/ConnectionCompleteNotification.cs

@@ -52,6 +52,16 @@ namespace Microsoft.SqlTools.ServiceLayer.Connection.Contracts
         /// The type of connection that this notification is for
         /// </summary>
         public string Type { get; set; } = ConnectionType.Default;
+
+        /// <summary>
+        /// Gets or sets a boolean value indicates whether the current server version is supported by the service.
+        /// </summary>
+        public bool IsSupportedVersion { get; set; }
+
+        /// <summary>
+        /// Gets or sets the additional warning message about the unsupported server version.
+        /// </summary>
+        public string UnsupportedVersionMessage { get; set; }
     }
 
     /// <summary>