Add various uninterpreted bit tensor data types (try 2)
Summary:
This is a retry of https://github.com/pytorch/pytorch/pull/94992 which
was reverted due to CI issues.
This PR adds a set of unintrepreted data types on PyTorch which can be
used to implement experimental functionality out of core (think fp8,
int4, int16 quant, etc).
Test Plan:
```
python test/test_quantization.py -k TestBits
```
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