edit/revertCell (#268)

// edit/dispose -------------------------------------------------------------------------------
export interface EditDisposeParams extends IEditSessionOperationParams { }
export interface EditDisposeResult { }

* Initial plumbing for edit/revertCell

* Implementation of revert cell in the parents of the row edit base

* Adding unit tests

src/Microsoft.SqlTools.ServiceLayer/EditData/UpdateManagement/RowDelete.cs

@@ -81,6 +81,16 @@ namespace Microsoft.SqlTools.ServiceLayer.EditData.UpdateManagement
             return GetCommandText(GetWhereClause(false).CommandText);
         }
 
+        /// <summary>
+        /// This method should not be called. A cell cannot be reverted on a row that is pending
+        /// deletion.
+        /// </summary>
+        /// <param name="columnId">Ordinal of the column to update</param>
+        public override string RevertCell(int columnId)
+        {
+            throw new InvalidOperationException(SR.EditDataDeleteSetCell);
+        }
+
         /// <summary>
         /// This method should not be called. A cell cannot be updated on a row that is pending
         /// deletion.