Add CreatedDate and OriginalCreatedDate fields

Author: ma-chni

src/MigrationTools.Clients.TfsObjectModel/Endpoints/TfsWorkItemConvertor.cs

@@ -49,6 +49,8 @@ private SortedDictionary<int, RevisionItem> GetRevisionItems(RevisionCollection
                 Number = (int)x.Fields["System.Rev"].Value,
                 ChangedDate = (DateTime)x.Fields["System.ChangedDate"].Value,
                 OriginalChangedDate = (DateTime)x.Fields["System.ChangedDate"].Value,
+                CreatedDate = (DateTime)x.Fields["System.CreatedDate"].Value,
+                OriginalCreatedDate = (DateTime)x.Fields["System.CreatedDate"].Value,
                 Type = x.Fields["System.WorkItemType"].Value as string,
                 Fields = GetFieldItems(x.Fields)
             }).ToList();