ns for fx: clean up API naming (#53729)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/53729
Aligns the names of the three core APIs to the design doc.
New names:
```
// weights
_extract_weights_one_model
extract_weights
// unshadowed activations
_add_loggers_one_model
add_loggers
_extract_logger_info_one_model
extract_logger_info
// shadowed activations
add_shadow_loggers
extract_shadow_logger_info
```
Test Plan:
```
python test/test_quantization.py TestFXNumericSuiteCoreAPIs
python test/test_quantization.py TestFXNumericSuiteCoreAPIsModels
```
Imported from OSS
Reviewed By: hx89
Differential Revision: D26953071
fbshipit-source-id: dda6df1c26afd99dd7779e72e3eed2d3d72c8128
