Cleaning up onnx module imports to prepare for updating `__init__`.
- Simplify importing the `_C` and `_C._onnx` name spaces
- Remove alias of the symbolic_helper module in imports
- Remove any module level function imports. Import modules instead
- Alias `symbilic_opsetx` as `opsetx`
- Fix some docstrings
Requires:
- https://github.com/pytorch/pytorch/pull/77448
Pull Request resolved: https://github.com/pytorch/pytorch/pull/77423
Approved by: https://github.com/BowenBao
Summary:
These were indiscriminately dumping `onnx::` instructions into traces, and making it so you couldn't run the traces in the JIT interpreter
Pull Request resolved: https://github.com/pytorch/pytorch/pull/12803
Differential Revision: D10443526
Pulled By: jamesr66a
fbshipit-source-id: 07172004bf31be9f61e498b5772759fe9262e9b3
