Fix weight tensors in transformers optimizer not saved to external data (#17427)
Some initializers are added without raw=True flag. That causes those
tensors cannot be saved to external data. If those tensors exceed 2GB
in total, optimized model cannot be saved due to protobuf limit.
This change will save attention weights and bias in raw data.
Note: it is optional to use raw data for shape tensor since they are
tiny.
### Motivation and Context
https://github.com/microsoft/onnxruntime/issues/17212
https://github.com/microsoft/onnxruntime/issues/15349