Make index_add_ error if input source shape is wrong (#100321)
Fixes #92576 , checking the following as described in the documentation:
"source.shape[dim] == len(index) and source.shape[i] == self.shape[i] for i != dim"
Would be happy to iterate on this if there are any issues, and would be happy to implement the checking for the CUDA and MPS implementations of index_add_.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/100321
Approved by: https://github.com/lezcano
