feat: add nft(nf_util) package: resp(wrap status, data, msg ...); add config: enable_not_impled_handler(default return 501 not impled)

xtest/basic/basic.http

@@ -1,2 +1,6 @@
 ### basic - get
-GET http://127.0.0.1/hello/nf
+GET http://127.0.0.1/hello/nf
+
+
+### test resp error
+GET http://127.0.0.1/error

xtest/basic/main.go

@@ -1,24 +1,30 @@
 package main
 
 import (
+	"errors"
 	"github.com/loveuer/nf"
+	"github.com/loveuer/nf/nft/resp"
 	"log"
 	"net"
 	"time"
 )
 
 func main() {
-	app := nf.New()
+	app := nf.New(nf.Config{EnableNotImplementHandler: true})
 
 	app.Get("/hello/:name", func(c *nf.Ctx) error {
 		name := c.Param("name")
 		return c.JSON(nf.Map{"status": 200, "data": "hello, " + name})
 	})
+	app.Get("/not_impl")
 	app.Patch("/world", func(c *nf.Ctx) error {
 		time.Sleep(5 * time.Second)
 		c.Status(404)
 		return c.JSON(nf.Map{"method": c.Method, "status": c.StatusCode})
 	})
+	app.Get("/error", func(c *nf.Ctx) error {
+		return resp.RespError(c, resp.NewError(404, "not found", errors.New("NNNot Found"), nil))
+	})
 
 	ln, _ := net.Listen("tcp", ":80")
 	log.Fatal(app.RunListener(ln))