[Quant][Eager][improvement] Added 4 bit support for eager mode quantization flow (reland PR 69806) (#72277)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/72277
Minor modifications were made to support 4 bit embedding quantized module in eager mode quantization flow and to allow for testing of the changes
Test Plan:
In pytorch main dir, execute
```
python test_quantization.py TestPostTrainingStatic.test_quantized_embedding
```
Reviewed By: jerryzh168
Differential Revision: D33994545
Pulled By: dzdang
fbshipit-source-id: faafad54b7b07fc393904ba55c2b2ac934c276f7
(cherry picked from commit 042ffb2091dd85a6273c97438dc7e913fcd03224)
