[DataPipe] Adding interface for MapDataPipes (#69648)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/69648
cc VitalyFedyunin ejguan NivekT
Test Plan: Imported from OSS
Reviewed By: ejguan
Differential Revision: D32989066
Pulled By: NivekT
fbshipit-source-id: ef96bcd4ac4d7a576fdd2a3fb4ef52ae6a902e10
