onnxruntime

[js/web] support flag 'optimizedModelFilePath' in session options (#14355)

### Description
* Support flag 'optimizedModelFilePath' in session options.

In Node.js, the model will be saved into filesystem just like its
behaviour on native platforms.

In browser, the new model is not saved to filesystem. the file path is
ignored. Instead, a new pop-up window will be launched in browser and
user can 'save' the file as onnx model.

* Add corresponding commandline args for the following session option
flags:
    - optimizedModelFilePath
    - graphOptimizationLevel