REGTESTS: http: add a test to validate chunked responses delivery

I've had this test here never committed over the last 2.5 years, that
works fine and I didn't notice it was not part of the tree. It makes a
server return odd-sized chunked responses with short pauses between half
of thems and verifies they're not truncated on the client. It may detect
eventually state machine breakages, so better commit it.

(cherry picked from commit 42faad48f619c3e0b2cada4b3fdad7e2a08aecad)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
1 file changed