feature: adding support for AsyncInferenceConfig in endpoint config

The EndpointConfig constructor could be extended to support passing in AsyncInferenceConfig
which includes configuration as shown here in the doc [API_AsyncInferenceConfig](https://docs.aws.amazon.com/sagemaker/latest/APIReference/API_AsyncInferenceConfig.html)
In this way would be possible to create an EndpountConfig supporting [Asynchronous Inference](https://docs.aws.amazon.com/sagemaker/latest/dg/async-inference.html).

Start at the EndpointConfig constructor and compare its current configuration inputs with the AWS API_AsyncInferenceConfig documentation linked in the issue. Trace how endpoint configuration is represented and verify that the resulting configuration supports the asynchronous inference settings described by AWS; done means users can create an EndpointConfig with AsyncInferenceConfig.

Written by the indexing model from the issue text.