Rename torchbench, datasets, and HF repo

[PaliC]

The purpose of this PR is to rename several things for more accurate communication during our release. I made the following renames:

TorchBenchSuite → ModelTracesSuite
datasets → test_suites
huggingface_op_trace → backendbench_tests

Motivation for the renames

TorchBenchSuite → ModelTracesSuite

TorchBench is a misnomer here, as this test suite actually contains models from HuggingFace Transformers, TIMM, and TorchBench (which is actually the smallest contributor iirc). ModelTraces better captures that the test suite consists of model traces used in PyTorch CI. Given that we plan to expand this test suite primarily through additional traces, this name is more appropriate.

datasets → test_suites

This was poor naming on my part. When creating new test suites, I incorrectly called them datasets, which caused confusion.

huggingface_op_trace → backendbench_tests

I updated the repository name where ModelTracesSuite lives to correct the misnomer—it's a repository of test suites, not HuggingFace op traces.

[msaroufim]

I'm not a big fan of the new names or the old ones :P. Just so you don't get randomized updating the PR mind discussing these in an issue instead? Personally I'd prefer things that fully explain what something is like HF_TOP_MODEL_SHAPE. Tests is vague it could refer to things in test it could refer to suite? datasets could mean anything