[quant][be] Cleanup test cases for eager mode workflow (#69880)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/69880
Making the test cases more standardized, in general we would like to have
```
TestQuantizeEager,
TestQuantizeEagerOps,
TestQuantizeEagerModels,
```
but currently since we have separate ptq static, ptq dynamic and qat static apis, we only partially cleaned
up the test cases, we can merge all of them later when we merge all the apis
Test Plan:
python test/test_quantization.py
Imported from OSS
Reviewed By: supriyar
Differential Revision: D33081418
fbshipit-source-id: fcb96559b76bbc51eb1b0625e0d4b193dbb37532
