[WIP]Adds _weight_int8pack_mm pass for woq-int8

[xiaowangintel]

Summary
This pr add aten._weight_int8pack_mm pass to replace mm + mul in woq-int8 model.

Motivation
Improve performance for woq-int8 inference.

Result:
We can get correct result on Intel GPU.

[pytorch-bot]

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❌ 6 New Failures

As of commit 39d2971 with merge base 5e90c47 ():

NEW FAILURES - The following jobs have failed:

• Run 1xH100 Tests / test (H100, linux.aws.h100, --pre torch torchvision torchaudio fbgemm-gpu-genai --index-url https... / linux-job (gh)
  test/integration/test_integration.py::TestSaveLoadMeta::test_save_load_int8woqtensors_5_cuda
• Run 1xL4 Tests / test (SM-89, linux.g6.4xlarge.experimental.nvidia.gpu, --pre torch --index-url https://download.p... / linux-job (gh)
  test/integration/test_integration.py::TestSaveLoadMeta::test_save_load_int8woqtensors_5_cuda
• Run Regression Tests / test (CUDA 2.6, linux.g5.12xlarge.nvidia.gpu, torch==2.6.0, cuda, 12.6) / linux-job (gh)
  test/quantization/test_quant_api.py::TestQuantFlow::test_quantized_tensor_subclass_int8_wo
• Run Regression Tests / test (CUDA 2.7, linux.g5.12xlarge.nvidia.gpu, torch==2.7.0, cuda, 12.6) / linux-job (gh)
  test/quantization/test_quant_api.py::TestQuantFlow::test_quantized_tensor_subclass_int8_wo
• Run Regression Tests / test (CUDA 2.8, linux.g5.12xlarge.nvidia.gpu, torch==2.8.0, cuda, 12.6) / linux-job (gh)
  test/quantization/test_quant_api.py::TestQuantFlow::test_quantized_tensor_subclass_int8_wo
• Run Regression Tests / test-nightly (CUDA Nightly, linux.g5.12xlarge.nvidia.gpu, --pre torch --index-url https://downloa... / linux-job (gh)
  test/quantization/test_quant_api.py::TestQuantFlow::test_quantized_tensor_subclass_int8_wo

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[jerryzh168]

this is a code path for int8 cuda as well I think, changing it has a risk of perf regressions

also this is the older stack, I'd suggest to migrate first, WIP here for int8 + plain layout: #3038