Manage Request with shared_ptr

This is an attempt to solve a class of use-after-move bugs on the
Request objects which have popped up several times. This more clearly
identifies code which owns the Request objects and has a need to keep it
alive. Currently it's just the `Connection` (or `HTTP2Connection`)
(which needs to access Request headers while sending the response), and
the `validatePrivilege()` function (which needs to temporarily own the
Request while doing an asynchronous D-Bus call). Route handlers are
provided a non-owning `Request&` for immediate use and required to not
hold the `Request&` for future use.

Tested: Redfish validator passes (with a few unrelated fails).
Redfish URLs are sent to a browser as HTML instead of raw JSON.

Change-Id: Id581fda90b6bceddd08a5dc7ff0a04b91e7394bf
Signed-off-by: Jonathan Doman <jonathan.doman@intel.com>
Signed-off-by: Ed Tanous <ed@tanous.net>
diff --git a/http/http_request.hpp b/http/http_request.hpp
index d1a6ac0..d2a1e25 100644
--- a/http/http_request.hpp
+++ b/http/http_request.hpp
@@ -18,7 +18,8 @@
 
 struct Request
 {
-    boost::beast::http::request<bmcweb::HttpBody> req;
+    using Body = boost::beast::http::request<bmcweb::HttpBody>;
+    Body req;
 
   private:
     boost::urls::url urlBase;
@@ -32,9 +33,7 @@
     std::shared_ptr<persistent_data::UserSession> session;
 
     std::string userRole;
-    Request(boost::beast::http::request<bmcweb::HttpBody> reqIn,
-            std::error_code& ec) :
-        req(std::move(reqIn))
+    Request(Body reqIn, std::error_code& ec) : req(std::move(reqIn))
     {
         if (!setUrlInfo())
         {