[Feature Request] Support querying the device type to which the subgraph is assigned

[mingmingtasd]

Describe the feature request

The ORT PR Add API to get ep graph partitioning info already supports querying the ep name to which the subgraph is assigned, is it possible to also support querying the device type?

Describe scenario use case

The requirement is from webmachinelearning/webnn#836 by MLGraph.devices.

[adrastogi]

@mingmingtasd, will also use this to track the request to surface when fallback has happened (via the example you shared here:

onnxruntime/onnxruntime/core/providers/openvino/backends/basic_backend.cc

Line 123 in a3749f1

LOGS_DEFAULT(WARNING) << "Model compilation failed at OV NPU."

)