get_available_devices()

[alexewerlof]

Feature request

Add a function to get all the possible valid values of device in a given environment (e.g. node, electron, browser).

Motivation

We have ModelRegistery.get_available_dtypes() which is a huge help in user onboarding:

• Instead of guessing the best dtype for a given machine, we can let the users choose.
• We can try different values and see which one works (fallback mechanism).

But when it comes to device, we're left with guessing.

• auto has its own problems (types in example #1624)
• Without a list, the code for trying fallbacks relies on hard coded strings

The value is available as suportedDevices in onnx.js but not exposed externally.

Your contribution

I could implement a PR if needed.