[quant][graphmode][fx][refactor] Remove quantized_graph from Quantizer (#59031)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/59031
Trying to remove Quantizer class and split prepare and convert code
Test Plan:
python test/test_quantization.py TestQuantizeFx
python test/test_quantization.py TestQuantizeFxOps
Imported from OSS
Reviewed By: vkuzo
Differential Revision: D28724871
fbshipit-source-id: dad0332ba271c4cfb6ec1e8f2036443149b5bea4
