clean up transformers scripts (#17179)
(1) Remove class BertOptimizationOptions that has been deprecated a long
time ago
(2) Move sys path setttings to `__init__.py`, and update imports
(3) Fix bert_perf_test to run properly.
(4) Fix a onnx path in a whisper test case
(5) Fix a few typos
(6) Update comments in bert_perf_test regarding to graph inputs
