Fix support for SQL DW in Edit Data scenarios (#379)

- SQL DW does not support SESSIONPROPERTY. Verified that the correct return values are "true" for both values on all DW instances

src/Microsoft.SqlTools.ServiceLayer/Connection/ReliableConnection/ReliableSqlConnection.cs

@@ -512,6 +512,14 @@ SET NUMERIC_ROUNDABORT OFF;";
             Tuple<string,bool>[] sessionSettings = new Tuple<string,bool>[2];
 
             IDbConnection connection = originalCommand.Connection;
+            if (IsSqlDwConnection(connection))
+            {
+                // SESSIONPROPERTY is not supported. Use default values for now
+                sessionSettings[0] = Tuple.Create("ANSI_NULLS", true);
+                sessionSettings[1] = Tuple.Create("QUOTED_IDENTIFIER", true);
+            }
+            else
+            {
                 using (IDbCommand localCommand = connection.CreateCommand())
                 {
                     // Executing a reader requires preservation of any pending transaction created by the calling command
@@ -529,9 +537,10 @@ SET NUMERIC_ROUNDABORT OFF;";
                             Debug.Assert(false, "Reader cannot be empty");
                         }
                     }
-                return sessionSettings;
                 }
             }
+            return sessionSettings;
+        }
 
         private void SetSessionSettings(IDbConnection connection, params  Tuple<string, bool>[] settings)
         {