ns for fx: make NSTracer inherit from QuantizationTracer (#55505)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/55505
This necessary to add support in NS for QAT modules, to avoid
duplicating logic between NSTracer and QuantizationTracer.
The eng work to expose the custom module and class names to
the user will be in a future PR.
Test Plan:
```
python test/test_quantization.py TestFXNumericSuiteCoreAPIs
python test/test_quantization.py TestFXNumericSuiteCoreAPIsModels
```
Imported from OSS
Reviewed By: jerryzh168
Differential Revision: D27650407
fbshipit-source-id: 431f47c5353b41c11371c5efa79657bfd085459a
