🐛 fix: route naming when to use group in group.

[efectn]

If we use group in group, name of first group won't appear.

Code:

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

	a := app.Group("/a").Name("a.")

	b := a.Group("/b").Name("b.")
	b.Get("/hello/", func(c *fiber.Ctx) error {
		return c.SendString("d")
	}).Name("c")

	data, _ := json.MarshalIndent(app.Stack(), "", "  ")
	fmt.Print(string(data))
}

Old Output:

[
  [
    {
      "method": "GET",
      "name": "b.c",
      "path": "/a/b/hello/",
      "params": null
    }
  ],
  [
    {
      "method": "HEAD",
      "name": "",
      "path": "/a/b/hello/",
      "params": null
    }
  ],
  ...
]

New Output:

[
  [
    {
      "method": "GET",
      "name": "a.b.c",
      "path": "/a/b/hello/",
      "params": null
    }
  ],
  [
    {
      "method": "HEAD",
      "name": "",
      "path": "/a/b/hello/",
      "params": null
    }
  ],
  ...
]