Image classification can't run on CPU that doesn't support AVX instruction

### System information

- **OS version/distro**: Window10
- **.NET Version (eg., dotnet --info)**: 3.1.302

### Issue

We have a few users from Model Builder report on image classification failure because of loading error.
- https://github.com/dotnet/machinelearning-modelbuilder/issues/915
- https://github.com/dotnet/machinelearning-modelbuilder/issues/920

After some investigation, I think it is because their CPU is too old and doesn't support AVX instruction, which is used to build tensorflow after v1.6. **But I'm not too sure about it, and that conclusion need double check**.

In the meanwhile, it would be great if we can catch the instruction not support error from exception thrown by mlnet. Right now the error message is "Tensorflow exception triggered while loading model", which is not really helpful in debugging. Is it possible to have a new exception, or a specific error message to highlight the avx not support exception?