Reduce structured kernels' `set_output` boilerplate with new overloads.
Partially fix #69813
This PR does mainly 3 things:
1. Introduces new methods for the `MetaBase` API:
- `set_output_strided`: creates proxy tensors with exact strides, if strides don't match
- `set_output_contiguous`: alias for `set_output_strided` with contiguous strides
- `set_output_raw_strided`: does not create proxy tensors
2. Modifies codegen for handling proxy tensors:
- Creates a new field for out-of-place kernels: `proxy_output_`
- Implements `set_output_strided` by creating a proxy tensor if necessary
- Passes the proxy tensor to them `IMPL` function
- Copy the result back to the real output, in the end, whenever a proxy was created
3. Replace `set_output` by `set_output_raw_strided` for `TensorIterator*`
- Needed, since it overrides `set_output`
Pull Request resolved: https://github.com/pytorch/pytorch/pull/76096
Approved by: https://github.com/ezyang
