Implement `mul(dense, sparse), mul(sparse, dense)` for sparse COO tensors. (#81556)
As per title. Implemented with broadcasting and in-place support.
Follow-up : Backward implementation.
Fixes https://github.com/pytorch/pytorch/issues/3158
Fixes https://github.com/pytorch/pytorch/issues/4456
Fixes https://github.com/pytorch/pytorch/issues/46307
Pull Request resolved: https://github.com/pytorch/pytorch/pull/81556
Approved by: https://github.com/amjames, https://github.com/cpuhrsch
