Creates a transport socket for HTP/1.1 proxy support.
With the combination of the transport socket, and a filter putting the proxy stream info in place this will
redirect TCP connections to the proxy IP address
prefix TLS connections with cleartext CONECT headers to the destination host, and strip CONNECT response
change cleartext HTTP/1.1 to send fully qualified URLs
Risk Level: medium (intended as a no op but it does have data plane refactory)
Testing: new unit, integration tests
Docs Changes: n/a
Part of envoyproxy/envoy-mobile#1622
Signed-off-by: Alyssa Wilk <alyssar@chromium.org>
Mirrored from https://github.com/envoyproxy/envoy @ 095f4ca336d3d705e629b207fb2cbbc22d29db8f