Execution Provider bridge for TFLite Delegates for Coral Edge TPUs

[rgov]

ONNX Runtime cannot yet target Coral Edge TPU accelerators.

Coral normally uses Tensorflow Lite with a loadable TFLite Delegate that communicates with the hardware called libedgetpu.

It appears that the goals of ONNX Runtime Execution Providers and TFLite Delegates are similar so perhaps it would be possible to create a wrapper to bridge the APIs (docs). If such a bridge existed it would be possible to target Edge TPU devices.

TFLite can also target some of the same accelerators as ONNX Runtime (NNAPI, CoreML, etc.). Having the bridge could also be useful for debugging issues by reproducing them on an alternative code path.