where() function added as a Tensor method as well (#92849)
Fixes #88470
I added the "method" keyword in `aten/src/ATen/native/native_functions.yaml` for the function `where` with Scalar Overload.
This way, you can now use `Tensor.where()` with a scalar parameter the same way `torch.where()` can.
I added a test in `test/test_torch.py` as requested.
It uses the `where()` method on a tensor and then checks it has the same results as the `torch.where()` function.
The test is roughly the same as the one provided by the author of the issue.
PS: this is the second PR I make to resolve this issue, the first one is #92747. I had troubles with commit signatures and is therefore closed.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/92849
Approved by: https://github.com/albanD
