[ONNX] Rename constants for clarity (#84645)
Rename constants to make them more clear. Fix styles to upper case.
Removed `onnx_stable_opsets` because it can be computed from `ONNX_MIN_OPSET` and `ONNX_MAX_OPSET`.
Fixes #84643
Pull Request resolved: https://github.com/pytorch/pytorch/pull/84645
Approved by: https://github.com/BowenBao
