Refactor int4 and int8 weight only quantization to use `quantize` #1526

Job	Run time
test (CUDA 2.2.2, linux.g5.12xlarge.nvidia.gpu, torch==2.2.2, cuda, 12.1) / linux-job	15m 10s
test (CUDA 2.2.2, linux.g5.12xlarge.nvidia.gpu, torch==2.2.2, cuda, 12.1) / linux-job	15m 10s
test (CPU 2.2.2, linux.4xlarge, torch==2.2.2 --index-url https://download.pytorch.org/whl/cpu, cpu) / linux-job	4m 19s
test (CPU 2.2.2, linux.4xlarge, torch==2.2.2 --index-url https://download.pytorch.org/whl/cpu, cpu) / linux-job	4m 19s
test (CPU Nightly, linux.4xlarge, --pre torch --index-url https://download.pytorch.org/whl/nightl... / linux-job	4m 22s
test (CPU Nightly, linux.4xlarge, --pre torch --index-url https://download.pytorch.org/whl/nightl... / linux-job	4m 22s
test (CPU 2.3, linux.4xlarge, torch==2.3.0 --index-url https://download.pytorch.org/whl/cpu, cpu) / linux-job	4m 27s
test (CPU 2.3, linux.4xlarge, torch==2.3.0 --index-url https://download.pytorch.org/whl/cpu, cpu) / linux-job	4m 27s
test (CUDA 2.3, linux.g5.12xlarge.nvidia.gpu, torch==2.3.0, cuda, 12.1) / linux-job	21m 33s
test (CUDA 2.3, linux.g5.12xlarge.nvidia.gpu, torch==2.3.0, cuda, 12.1) / linux-job	21m 33s
test (CUDA Nightly, linux.g5.12xlarge.nvidia.gpu, --pre torch --index-url https://download.pytorc... / linux-job	20m 14s
test (CUDA Nightly, linux.g5.12xlarge.nvidia.gpu, --pre torch --index-url https://download.pytorc... / linux-job	20m 45s
	2h 20m 41s

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