Support for Infer within the Predictions

[sammartinez]

Is your feature request related to a problem? Please describe.
We currently don't have support for Predictions.Infer within the JS repo.

Additional context

• https://docs.aws.amazon.com/sagemaker/latest/APIReference/API_runtime_InvokeEndpoint.html

[icoxfog417]

Have this feature not implemented yet? To demonstrate machine learning model deployed in SageMaker Endpoint, I try to use Infer but not supported yet and there is not detail document about using Infer.

Referred document

• https://aws.amazon.com/blogs/mobile/announcing-the-new-predictions-category-in-amplify-framework/
• https://docs.amplify.aws/lib/predictions/intro/q/platform/js/