[quant][graphmode][fx][refactor] Remove find_matches from Quantizer class (#59037)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/59037
To remove Quantizer class and split prepare and convert functions to different files
Test Plan:
python test/test_quantization.py TestQuantizeFx
python test/test_quantization.py TestQuantizeFxOps
Imported from OSS
Reviewed By: vkuzo
Differential Revision: D28724865
fbshipit-source-id: 6c6824d0af7dd47d4c111d6a08e373bc65f33e08
