Move `components` to `torchbenchmark/_components` (#2201)
Summary:
When running as a package and user changed to a different directory, we need to also package the `components` directory.
Fixes https://github.com/pytorch/benchmark/issues/2049
Pull Request resolved: https://github.com/pytorch/benchmark/pull/2201
Reviewed By: aaronenyeshi
Differential Revision: D55024021
Pulled By: xuzhao9
fbshipit-source-id: 1352b075b376b14a885e2eb01cb72e627958f17c
