New test case for Expect header & checkExpectation event based on the
existing http test case.
PR-URL: https://github.com/nodejs/node/pull/15040
Refs: https://github.com/nodejs/node/issues/14985
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Yuta Hiroto <hello@about-hiroppy.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
