feat(router) add normalize-req-uri parameter

Use a self parameter(normalize_req_uri) of kong.router to load the new parameter.
It will be easier to add a new route parameter to control the URI normalization behavior in the future.

New feature for Kong#7913

Author: yankun-li-kong

kong/router.lua

@@ -1820,6 +1820,7 @@ function _M.new(routes)
 
   self.select = find_route
   self._set_ngx = _set_ngx
+  self.normalize_req_uri = routes.normalize_req_uri
 
   if subsystem == "http" then
     function self.exec(ctx)
@@ -1848,8 +1849,7 @@ function _M.new(routes)
           req_uri = sub(req_uri, 1, idx - 1)
         end
 
-        local normalize_req_uri = kong.configuration.normalize_req_uri
-        if normalize_req_uri == "on" then
+        if self.normalize_req_uri == "on" then
             req_uri = normalize(req_uri, true)
         end
       end

kong/runloop/handler.lua

@@ -688,6 +688,7 @@ do
   build_router = function(version)
     local db = kong.db
     local routes, i = {}, 0
+    routes.normalize_req_uri = kong.configuration.normalize_req_uri
 
     local err
     -- The router is initially created on init phase, where kong.core_cache is