refactor(http1): move upgrade state from body to head (#2353)

Move state required for protocol upgrades to head
representations, instead of associating it with the body.

Closes #2340.

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

src/proto/mod.rs

@@ -16,7 +16,7 @@ cfg_http2! {
 }
 
 /// An Incoming Message head. Includes request/status line, and headers.
-#[derive(Clone, Debug, Default, PartialEq)]
+#[derive(Debug, Default)]
 pub struct MessageHead<S> {
     /// HTTP version of the message.
     pub version: http::Version,
@@ -24,6 +24,9 @@ pub struct MessageHead<S> {
     pub subject: S,
     /// Headers of the Incoming message.
     pub headers: http::HeaderMap,
+
+    /// Extensions.
+    extensions: http::Extensions,
 }
 
 /// An incoming request message.