[nnc] Added micro-benchmark to show perf improvement with cat subgraph optimization (#59581)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/59581
Test Plan: Imported from OSS
Reviewed By: bertmaher
Differential Revision: D28955317
Pulled By: navahgar
fbshipit-source-id: 53bb3dbfafbd3b146063f305523c2e6ec96cf6b8
