move RoutedDecoder Dataset to DataPipe (#51704)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/51704
Test Plan: Imported from OSS
Reviewed By: ejguan
Differential Revision: D26245910
Pulled By: glaringlee
fbshipit-source-id: 91e3c9f8a6c1209c1a1a752ba29a80dbd9bf4119
