move Tar Dataset to Tar DataPipe (#51398)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/51398
Test Plan: Imported from OSS
Reviewed By: ejguan
Differential Revision: D26162319
Pulled By: glaringlee
fbshipit-source-id: a84879fe4ca044e34238d5e1d31a245d4b80ae8e
