Type hint for ORTModule (#15938)
### Type hint for ORTModule
Add Type hint for ORTModule
Refine comments.
The reason of removing theinterface execution_session_run_forward from
`orttraining/orttraining/python/training/ortmodule/_graph_execution_manager.py`:
PR
https://github.com/microsoft/onnxruntime/commit/cc275e75294fa783ce3cb75aec5f16e18cb71821#diff-497e18dc8878818205b81fd80f85942548d8aa15d0f1204ce3e3d9795e3dd195
and some commit before it breaks the function interface contracts
between parent calss _graph_execution_manager.py and its children
_training_manager.py and _inference_manager.py. So there is no need to
have this interface.
### Other EE work opportunities
1. Use logger correctly.
2. Remove few duplication logic parsing input/output recursively.
3. Clean up environment variable usage.
