Standardize the incubated HTTP Client API introduced in JDK 9, via JEP 110, and updated in JDK 10 ([JEP 321](http://openjdk.java.net/jeps/321)).

The HTTP Client has been standarized in Java 11. As part of this work the previously incubating API, located in the ` jdk.incubator.http` package, has been removed. At a very minimum, code that uses types from the `jdk.incubator.http` package will need to be updated to import the HTTP types from the standard package name, `java.net.http.`