Move fx2trt test out of PyTorch repo (#72570)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/72570
Following first diff to further clean up fx2trt out of pytorch codebase.
Test Plan:
```
buck test mode/dev-nosan deeplearning/trt/fx2trt_oss/test/core:
```
Reviewed By: suo
Differential Revision: D34096297
fbshipit-source-id: c3230769b1e2238376e9cf79524f5ed1a605b049
(cherry picked from commit 0a129ad2a0216780566c8ef3b8045f109e6f315e)
