[caffe2] Add support for int32 lengths in BatchSparseToDense (#58062)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/58062
Make templated function to make sure BatchSparseToDense supports int32 lengths/indices
Test Plan:
```buck test //caffe2/caffe2/python/operator_test:batch_sparse_to_dense_op_test
```
Reviewed By: khabinov
Differential Revision: D28271423
fbshipit-source-id: 41b88b7a3663616b533aaf4731ff35cdf6ec4c85
