sess.Regenerate() issue 🐛

[EugeneTorap]

Fiber version
v2.13.0

Issue description
I want to write a refresh api for regenerating a session but it doesn't regenerate session every second call.
When call refresh in first time the fresh of sess is true and I have a session. In second time the fresh of sess is false and sess.Save() doesn't save a new session. In third time the fresh of sess is true and I have a session.
I think issue is sess.Regenerate() does't set s.fresh = true.

Code snippet

package main

import (
	"fmt"
	"github.com/gofiber/fiber/v2"
	"github.com/gofiber/fiber/v2/middleware/session"
	"log"
)

var store = session.New()

func main() {
	app := fiber.New()

	app.Get("/", func(ctx *fiber.Ctx) error {
		sess, err := store.Get(ctx)
		if err != nil {
			return err
		}
		name := sess.Get("name")
		str := fmt.Sprintf("%v", name)
		return ctx.SendString(str)
	})
	app.Get("/refresh", func(ctx *fiber.Ctx) error {
		sess, err := store.Get(ctx)
		if err != nil {
			return err
		}

		fmt.Println(sess.ID(), sess.Fresh())
		if err = sess.Regenerate(); err != nil {
			return err
		}

		sess.Set("name", "bob")

		fmt.Println(sess.ID(), sess.Fresh())
		if err = sess.Save(); err != nil {
			return err
		}

		fmt.Println("The session is refreshed")
		return ctx.SendString("The session is refreshed")
	})
	log.Fatal(app.Listen(":8080"))
}

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[hi019]

You're right, the issue is with Session.fresh. The session is only saved if it's new:

https://github.com/gofiber/fiber/blob/master/middleware/session/session.go#L141-L143

Calling Session.Regenerate and then Session.Save doesn't update the cookie, so in the next request the browser sends the previous session ID which was deleted.