fixed bug with IPersistentRepresentation.Update and timestamp propagation (#4684)

* moved DateTimes to Utc to make them monotonic

Author: Aaronontheweb

src/contrib/persistence/Akka.Persistence.Sql.Common/Journal/BatchingSqlJournal.cs

@@ -1210,7 +1210,7 @@ private async Task HandleWriteMessages(WriteMessages req, TCommand command)
                                     persistent = persistent.WithPayload(tagged.Payload);
                                 }
 
-                                WriteEvent(command, persistent.WithTimestamp(DateTime.Now.Ticks), tagBuilder.ToString());
+                                WriteEvent(command, persistent.WithTimestamp(DateTime.UtcNow.Ticks), tagBuilder.ToString());
 
                                 await command.ExecuteNonQueryAsync();
 

src/contrib/persistence/Akka.Persistence.Sql.Common/Journal/QueryExecutor.cs

@@ -684,7 +684,7 @@ public virtual async Task InsertBatchAsync(DbConnection connection, Cancellation
                     var evt = entry.Key;
                     var tags = entry.Value;
 
-                    WriteEvent(command, evt.WithTimestamp(DateTime.Now.Ticks), tags);
+                    WriteEvent(command, evt.WithTimestamp(DateTime.UtcNow.Ticks), tags);
                     await command.ExecuteScalarAsync(cancellationToken);
                     command.Parameters.Clear();
                 }