Feature/save results as csv (#33)

* Code changes to save results as csv

*  changes to save resultset as csv

* removed csvHelper

* Retrieve right resultSet after batch execution]

* code clean up

* encode column names and use string.Join

* code review changes - property fix and rowBuilder removal

* changes to fix execution tests

* Code clean up

* Code clean up

* Test save as CSV

* Fix tests for Mac/Linux

* Add doc comment

* Add doc comments

* Delete file if exception occurs

src/Microsoft.SqlTools.ServiceLayer/QueryExecution/ResultSet.cs

@@ -111,6 +111,14 @@ namespace Microsoft.SqlTools.ServiceLayer.QueryExecution
         /// </summary>
         public long RowCount { get; private set; }
 
+        /// <summary>
+        /// The rows of this result set
+        /// </summary>
+        public IEnumerable<object[]> Rows
+        {
+            get { return FileOffsets.Select(offset => fileStreamReader.ReadRow(offset, Columns)); }
+        }
+
         #endregion
 
         #region Public Methods