[feature] Allow setting read timeout of underlying async HTTP client Request

Be able to set wsRequest.withReadTimeout(duration), mainly to avoid read timeout exceptions in long-running stream requests.

Play WS Version (2.5.x / etc)

2.6+

API (Scala / Java / Neither / Both)

Both

Operating System (Ubuntu 15.10 / MacOS 10.10 / Windows 10)

Use uname -a if on Linux.

JDK (Oracle 1.8.0_72, OpenJDK 1.8.x, Azul Zing)

Paste the output from java -version at the command line.

Library Dependencies

If this is an issue that involves integration with another system, include the exact version and OS of the other system, including any intermediate drivers or APIs i.e. if you connect to a PostgreSQL database, include both the version / OS of PostgreSQL and the JDBC driver version used to connect to the database.

Expected Behavior

Example:

• Set wsRequest.withReadTimeout(Duration.Inf).
• Initiate a long-running streaming request with .stream.
• Stop getting these exceptions:

Caused by: java.util.concurrent.TimeoutException: Read timeout to localhost/127.0.0.1:5984 after 120000 ms
        at play.shaded.ahc.org.asynchttpclient.netty.timeout.TimeoutTimerTask.expire(TimeoutTimerTask.java:43)
        at play.shaded.ahc.org.asynchttpclient.netty.timeout.ReadTimeoutTimerTask.run(ReadTimeoutTimerTask.java:54)
        at play.shaded.ahc.io.netty.util.HashedWheelTimer$HashedWheelTimeout.expire(HashedWheelTimer.java:663)
        at play.shaded.ahc.io.netty.util.HashedWheelTimer$HashedWheelBucket.expireTimeouts(HashedWheelTimer.java:738)
        at play.shaded.ahc.io.netty.util.HashedWheelTimer$Worker.run(HashedWheelTimer.java:466)
        at java.lang.Thread.run(Thread.java:748)

Actual Behavior

There's currently no way to set read timeout, which defaults to 120000ms.

Start at the wsRequest API and trace how requests reach the underlying async HTTP client. Check how Scala and Java request APIs configure streaming requests, then verify that a configurable read timeout, including Duration.Inf, prevents the reported timeout in long-running streams.