Update on "[ET-VK][Ops] aligning Q/DQ/CQP op inputs with ATen impl"

# Context

A few operators have been recently created, namely:
- quantize_per_tensor
- quantize_per_token
- dequantize_per_tensor
- dequantize_per_token
- choose_qparams.tensor
- choose_qparams_per_token_asymmetric

They don't have a namespace associated with them, and since we are trying to align with the ATen implementation in their respective quantized_decomposed namespace, this diff is necessary to align in that regard. Furthermore, our operators need to match inputs with the ATen version, so we also pass dtypes.

# Changes

The primary change is adding the namespace quantized_decomposed to all the above named operators. Furthermore, we change the testing framework to pass dummy dtypes that is expected for the ATen implementation. We also change the `choose_qparams` logic to properly pass the eps, since this is actually a relevant variable and cannot be set by default, despite the existing op_quantize cpu reference in executorch not distinctly using this variable.

Differential Revision: [D77746144](https://our.internmc.facebook.com/intern/diff/D77746144/)

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Author: morelos