Update xnnpack graph schema to use xnode and xvalue (#89036)
There are different nodes definition like [Node in autograd](https://www.internalfb.com/code/fbsource/fbcode/caffe2/torch/csrc/autograd/function.h?lines=108-609&reveal=108-609) and onnxnodes and etc. Understand namespace can be used where nodes from definition are used together, however it's still better to slightly differentiate the name.
Differential Revision: [D41002324](https://our.internmc.facebook.com/intern/diff/D41002324/)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/89036
Approved by: https://github.com/mcr229
