bmcweb: Add JSON response to /logout

When logging out of the API, there was no JSON text response.
This implements the requested feature.

Tested: Verified appropriate response is generated when /logout
        is called

E.g.
curl -c cjar -b cjar -k -X POST \
  -H "Content-Type: application/json" \
  -H "X-Auth-Token: g3Heq5rYsz1j0iv4MbUp" \
  -d '{"data": [ ] }' \
  https://${bmc}/logout
{
  "data": "User 'root' logged out",
  "message": "200 OK",
  "status": "ok"
}

Change-Id: I905f5a0855abaa76ae57cf32b8bae758722f6b9f
Signed-off-by: Anthony Wilson <wilsonan@us.ibm.com>
diff --git a/include/token_authorization_middleware.hpp b/include/token_authorization_middleware.hpp
index c5c6523..697e400 100644
--- a/include/token_authorization_middleware.hpp
+++ b/include/token_authorization_middleware.hpp
@@ -438,6 +438,11 @@
                     .session;
             if (session != nullptr)
             {
+                res.jsonValue = {
+                    {"data", "User '" + session->username + "' logged out"},
+                    {"message", "200 OK"},
+                    {"status", "ok"}};
+
                 persistent_data::SessionStore::getInstance().removeSession(
                     session);
             }