[quant][fx] Add node name as prefix to observer module name (#44765)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/44765
Test Plan:
python test/test_quantization.py TestQuantizeFx.test_save_observer_state_dict
Imported from OSS
Reviewed By: jerryzh168
Differential Revision: D23741355
fbshipit-source-id: 7185ceae5b3b520ac0beebb627c44eab7ae7d231
