Add a standard BodyHandler and BodyPublisher

Since Java 11, there is the new HttpClient API.

However, to use it with JSON, it is always required to create an adapter class that converts a JSON that comes in String/InputStream to a Java object.

Having standard BodyHandler and BodyPublisher could easy the work done in the client side to interact with the HttpClient API.

There are already some Colletors in the API to interact with streams in Java 8, so I guess adding BodyHandlers and BodyPublisher would be possible too.

I just don't know which spec would be better to include this, if Jakarta Json Processing or Jakarta Json Binding.

Thoughts?

https://docs.oracle.com/en/java/javase/11/docs/api/java.net.http/java/net/http/HttpClient.html
https://docs.oracle.com/en/java/javase/11/docs/api/java.net.http/java/net/http/HttpResponse.BodyHandler.html
https://docs.oracle.com/en/java/javase/11/docs/api/java.net.http/java/net/http/HttpRequest.BodyPublisher.html

Start by reviewing the linked Java HttpClient documentation for BodyHandler and BodyPublisher, then compare whether Jakarta JSON Processing or Jakarta JSON Binding fits the proposed integration. Done means reaching agreement on the target API and specification scope; the issue names no repository files or tests.

Written by the indexing model from the issue text.