[Model] 1.58bits BitNet Model Support

[LeiWang1999]

This pull request is a follow-up to PR #6036. In this PR, we introduce the BitNet model and provide an efficient inference kernel with the BitBLAS backend. Here are the performance benchmarks:

Model	Framework	BS16IN32OUT128	BS1IN512OUT1024	B32IN32OUT128
BitNet-3B-1.58bits	PyTorch	106.83	49.34	209.03
BitNet-3B-1.58bits	PyTorch-BitBLAS	240.33	103.09	493.31
BitNet-3B-1.58bits	vLLM-BitBLAS	379.25	117.43	752.55
BitNet-3B-1.58bits	vLLM-BitBLAS-CUDA-Graph	2543.58	1621.08	2731.79

To answer the question raised by @mgoin in PR #6036, I believe a new BitNet model is necessary because the open-source BitNet implementation provides a unique tokenizer and model architecture, which includes an additional RMS layer compared to LLaMA. Additionally, the BitNet integration example with llama.cpp also introduces a new model architecture (refer to: llama.cpp.pr.7931).

Example Usage:

from conftest import VllmRunner

# Test BitNET model with BitBLAS quantization
with VllmRunner(
    "hxbgsyxh/bitnet_b1_58-3B",
    dtype="half",
    quantization="bitnet_bitblas",
    enforce_eager=True,
    gpu_memory_utilization=0.5,
) as bitnet_model:
    bitbnet_outputs = bitnet_model.generate_greedy(
        ["Hi, tell me about Microsoft?"], max_tokens=128
    )
    print("bitnet_bitblas:")
    print(bitbnet_outputs[0][0])
    print(bitbnet_outputs[0][1])

# Test another BitBLAS model
with VllmRunner(
    "hxbgsyxh/bitnet_b1_58-3B_bitblas",
    dtype="half",
    quantization="bitblas",
    enforce_eager=True,
) as bitnet_model:
    bitbnet_outputs = bitnet_model.generate_greedy(
        ["Hi, tell me about Microsoft?"], max_tokens=128
    )
    print("bitblas:")
    print(bitbnet_outputs[0][0])
    print(bitbnet_outputs[0][1])

• pr [Kernel] Support Microsoft Runtime Kernel Lib for our Low Precision Computation #6036 should be merged

[github-actions]

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[DarkLight1337]

Sorry for the long delay, @mgoin can you follow up on this and the previous PR?

A quick heads-up that the new locations of the model tests have been adjusted in #7820, so please merge from main.