[fx2trt] re-enable profiler and some miscs for TRTModule (#65072)

[fx2trt] re-enable profiler and some miscs for TRTModule (#65072)

Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/65072

Previously disabled attaching trt profiler to exec context in TRTModule because https://fburl.com/mc33n880 states that `enqueue()` doesn't support profiling. Seems to be a lie though. Re-enable attaching profiler in this diff.

Also added a bunch of checks for dtype and shape, and fixed saving state_dict and loading back.

Test Plan: buck run mode/opt -c python.package_style=inplace -j 40 deeplearning/trt/fx2trt:acc2trt_test

Reviewed By: yinghai

Differential Revision: D30962757

fbshipit-source-id: 9c664b0500a8169b7952f6f912239a5a05772aea