add some simple function to request and response class

Created by: manageryzy

add request->parse_post() request->parse_cookies() to request add response->set_MIME response->headers response->set_cookie response->send_headers to response

this a simple demo

server.default_resource["GET"] = [&server,&token](std::shared_ptr<HttpServer::Response> response, std::shared_ptr<HttpServer::Request> request)
		{
			try
			{
				auto web_root_path = std::filesystem::canonical(".");
				auto path = std::filesystem::canonical(web_root_path / request->path);
				//Check if path is within web_root_path
				if (std::distance(web_root_path.begin(), web_root_path.end()) > std::distance(path.begin(), path.end()) ||
					!std::equal(web_root_path.begin(), web_root_path.end(), path.begin()))
					throw std::invalid_argument("path must be within root path");
				if (std::filesystem::is_directory(path))
					path /= "index.html";

				auto ifs = std::make_shared<std::ifstream>();
				ifs->open(path.string(), std::ifstream::in | std::ios::binary | std::ios::ate);

				auto cookies = request->parse_cookies();
				for (auto cookie : cookies)
				{
					std::cout << cookie.first << " : " << cookie.second << std::endl;
				}

				if (*ifs)
				{
					auto length = ifs->tellg();
					ifs->seekg(0, std::ios::beg);

					response->set_MIME(path.extension().string());
					response->headers.emplace("Content-Length", std::to_string(length));
					response->headers.emplace("Cache-Control", "max-age=3600");
					response->set_cookie("tooken", "0", std::time(nullptr) + 1000);
					response->send_headers();
					default_resource_send(server, response, ifs);
				}
				else
					throw std::invalid_argument("could not read file:" + path.string());
			}
			catch (const std::exception& e)
			{
				std::string content = "Could not open path " + request->path + ": " + e.what();
				*response << "HTTP/1.1 404 Not Found\r\nContent-Length: " << content.length() << "\r\n\r\n" << content;
			}
		};