[Cuda] Refactor GroupNorm (#19146)
Split GroupNorm implementation into multiple files, to make ROCm EP can
reuse cuda code.
Related PR: https://github.com/microsoft/onnxruntime/pull/19158
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Co-authored-by: Peixuan Zuo <peixuanzuo@microsoft.com@orttrainingdev7.d32nl1ml4oruzj4qz3bqlggovf.px.internal.cloudapp.net>
