default and custom error pages response

+ refactoring in response.cpp (functions split)
+ added Client::clear()
+ added replace_all_substr() in utils.cpp

srcs/webserv/base.cpp

@@ -12,6 +12,8 @@ Webserv::Webserv()
 		throw std::runtime_error("Epoll init");
 	}
 
+	_init_http_status_map();
+
 	std::signal(SIGPIPE, signal_handler);
 	std::signal(SIGINT, signal_handler);
 }