Refactoring ORTTrainer tests (#206)
* Add decorator for ort training
* Add basic integration tests
* Update hub tester with optimum utils
* Add optuna test
* Modify run.sh
* Add HP search tests
* Add optimizer choice tests
* Add Seq2Seq tests
* Modify CI for ORT training
* Fix fp16 args
* Fix indent of ort fused optimizer mock
* Fix sigopt requirement condition
