Better support for unicode path and values.

Added WSF_REQUEST.percent_encoded_path_info: READABLE_STRING_8
    to keep url encoded path info, as it is useful for specific component

The router is now using WSF_REQUEST.percent_encoded_path_info
    since URI_TEMPLATE are handling URI (and not IRI)
    this fixes an issue with unicode path parameters.

This should not break existing code, and this fixes various unicode related issues related
   to PATH parameter and path info
   but also any component using file names.

(required EiffelStudio >= 7.2)

examples/tutorial/step_4/hello/src/user_message_handler.e

@@ -10,6 +10,10 @@ class
 
 inherit
 	WSF_URI_TEMPLATE_RESPONSE_HANDLER
+	SHARED_WSF_PERCENT_ENCODER
+		rename
+			percent_encoder as url_encoder
+		end
 
 feature -- Access
 
@@ -75,7 +79,8 @@ feature -- Access
 
 	url_encoded_string (s: READABLE_STRING_32): STRING_8
 		do
-			Result := (create {UTF8_URL_ENCODER}).encoded_string (s)
+			create Result.make (s.count)
+			url_encoder.append_percent_encoded_string_to (s, Result)
 		end
 
 	html_decoded_string (v: READABLE_STRING_32): READABLE_STRING_32