[core][pruning][feature] cuSPARSELt kernels and ops (#102133)
This PR contains two new private ops, added for cuSPARSELt support.
These ops call into the cuSPASRELt kernels using the bindings they
provide. For more information, see the documentation
[here](https://docs.nvidia.com/cuda/cusparselt/index.html).
The two new private ops added are:
```
_cslt_compress()
_cslt_sparse_mm()
```
_cslt_compress is an op that reuturns the compressesed matrix given a
sparse matrix that is passed in.
_cslt_sparse_mm is an op that expects a compressed matrix (the result of
_cslt_compress) and a dense matrix and performs sparse-dense matmul
These ops will throw runtime errors if they cusparselt is not present.
This PR also modifies the test and tensor sublass to reflect the new
cuSPARSELt support.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/102133
Approved by: https://github.com/cpuhrsch
