torch.ao migration: numeric suite, eager and fx (#64817)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/64817
This migrates `torch.quantization._numeric_suite` to `torch.ao.ns._numeric_suite`, and `torch.quantization._numeric_suite_fx` to `torch.ao.ns._numeric_suite_fx`.
1. move the files
```
HG: move eager mode
hg mv caffe2/torch/quantization/_numeric_suite.py caffe2/torch/ao/ns/
HG: move fx
hg mv caffe2/torch/quantization/_numeric_suite_fx.py caffe2/torch/ao/ns/
hg mv caffe2/torch/quantization/ns/* caffe2/torch/ao/ns/fx/
```
2. create new versions of `_numeric_suite.py` and `_numeric_suite_fx.py` with
imports
3. update all FB callsites
Test Plan: buck test mode/dev //caffe2/test:quantization
Reviewed By: z-a-f
Differential Revision: D30867538
fbshipit-source-id: 120ee830434ca490c1183a187a518eebcbbaf22c
