Port Tensor-RT and model compatibility tests to FX

[Christina-Young-NVIDIA]

No description provided.

[Christina-Young-NVIDIA]

To find any FX2TRT / dynamo gaps.

[gs-olive]

Currently, the TorchScript path routinely tests model compatibility for ResNet18, MobileNetV2, EfficientNetB0, ResNet18 with Half precision, and HuggingFace BERT base uncased. I have added a PR which tests the FX path (via specifying ir="fx" directly in torch_tensorrt.compile(...)) for all of these models except BERT, which currently fails to compile with this method and also does not compile using torch_tensorrt.fx.compile(...) with either is_aten=True or is_aten=False, via the current main branch (deda87b). The model also fails to compile with torch._dynamo.optimize(...). An issue will be raised regarding compilation of HuggingFace BERT in FX. This (current) investigative issue will be closed and the PR will remain as a draft until BERT model compilation in FX is supported.