[quant][core][better-engineering] Rename files in quantized/cuda directory to conform with non-quantized countertpart filenames #77431

Summary:
Names of analogous files in quantized directory (previously snake case) were inconsistent with
their non-quantized filename counterparts (pascal case). This is the fourth of a series of PRs that changes
all files in quantized (and sub-directories) dir to have pascal case.

Some files have not been renamed as it is causing issues related to
custom class with import torch at runtime.

Test Plan:
```
python test/test_quantization.py

```

Pull Request resolved: https://github.com/pytorch/pytorch/pull/77436

Approved by: https://github.com/jerryzh168
diff --git a/aten/src/ATen/native/quantized/cuda/affine_quantizer.cu b/aten/src/ATen/native/quantized/cuda/AffineQuantizer.cu
similarity index 100%
rename from aten/src/ATen/native/quantized/cuda/affine_quantizer.cu
rename to aten/src/ATen/native/quantized/cuda/AffineQuantizer.cu
diff --git a/aten/src/ATen/native/quantized/cuda/embedding_bag.cu b/aten/src/ATen/native/quantized/cuda/EmbeddingBag.cu
similarity index 100%
rename from aten/src/ATen/native/quantized/cuda/embedding_bag.cu
rename to aten/src/ATen/native/quantized/cuda/EmbeddingBag.cu
diff --git a/aten/src/ATen/native/quantized/cuda/fake_quantize_core.cu b/aten/src/ATen/native/quantized/cuda/FakeQuantizeCore.cu
similarity index 100%
rename from aten/src/ATen/native/quantized/cuda/fake_quantize_core.cu
rename to aten/src/ATen/native/quantized/cuda/FakeQuantizeCore.cu
diff --git a/aten/src/ATen/native/quantized/cuda/fused_obs_fake_quant.cu b/aten/src/ATen/native/quantized/cuda/FusedObsFakeQuant.cu
similarity index 100%
rename from aten/src/ATen/native/quantized/cuda/fused_obs_fake_quant.cu
rename to aten/src/ATen/native/quantized/cuda/FusedObsFakeQuant.cu
diff --git a/aten/src/ATen/native/quantized/cuda/int_repr_quant.cu b/aten/src/ATen/native/quantized/cuda/IntReprQuant.cu
similarity index 100%
rename from aten/src/ATen/native/quantized/cuda/int_repr_quant.cu
rename to aten/src/ATen/native/quantized/cuda/IntReprQuant.cu
diff --git a/aten/src/ATen/native/quantized/cuda/make_quantized_tensor.cu b/aten/src/ATen/native/quantized/cuda/MakePerTensorQuantizedTensor.cu
similarity index 100%
rename from aten/src/ATen/native/quantized/cuda/make_quantized_tensor.cu
rename to aten/src/ATen/native/quantized/cuda/MakePerTensorQuantizedTensor.cu