Middlewares not being applied

[EstebanBorai]

Describe the bug
Currently middlewares applied using the middleware method from a Graphul instance,
are initialized but are not being applied as part of consuming HTTP Requests.

use std::time::Duration;

use graphul::{http::Methods, Graphul, middleware::limit::RateLimitLayer};

#[tokio::main]
async fn main() {
  tracing_subscriber::fmt::init();

  let mut app = Graphul::new();

  app.get("/noop", || async {
    "hello world!2"
  });

  app.middleware(RateLimitLayer::new(2, Duration::from_secs(100)));

  app.get("/", || async {
    "hello world!"
  });

  app.run("127.0.0.1:8000").await;
}

To Reproduce
Steps to reproduce the behavior:

1. Create an instance of Graphul similar to how its done above
2. Apply a middleware of your choice (This PR contains a dumb middleware for testing)
3. Check for logs on terminal

Expected behavior

The middleware is applied

Screenshots

N/A

Desktop (please complete the following information):

• OS: macOS, Linux
• Browser N/A
• Version 0.5.5 (Forked from main on commit: 58b1cb2)

Smartphone (please complete the following information):
N/A

Additional context
N/A