✨ feature: route constraints

[efectn]

Close: #1903

Example:

app.Get("/:test<min(5)>", func(c *fiber.Ctx) error {
	return c.SendString(c.Params("test"))
})

app.Get("/:test<int;min(5)>", func(c *fiber.Ctx) error {
	return c.SendString(c.Params("test"))
})

To-Do:

• Tests and benchmarks.
• Multiple constraints.
• Add customization for regex matching.
• Performance checks.

[efectn]

should we skip or return false when consantraint not found?

[ReneWerner87]

Please add more benchmark tests, so we can keep an eye on the most important thing -> the performance