Replace split-squeeze pattern (#101765)
Replaces split-squeeze (same dimension) with an unbind. This will be used in combination with later patterns to remove the unbind if it follows a cat/stack
Differential Revision: [D45758181](https://our.internmc.facebook.com/intern/diff/D45758181/)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/101765
Approved by: https://github.com/jansel
