feat: improve log when starting the API

Added the URL where the API is running.

```
2024-01-09T16:29:46.911284166+00:00 [API][INFO] API server started on http://127.0.0.1:1212
```

Some hosting services parse the application log output to discover
services. For example, GitHub Codespaces can use that into to
automatically do port forwarding.

Besides, it's also useful for development when you are using random
ports and to see what services are you running.

src/servers/apis/server.rs

@@ -30,7 +30,7 @@ use axum_server::tls_rustls::RustlsConfig;
 use axum_server::Handle;
 use derive_more::Constructor;
 use futures::future::BoxFuture;
-use log::error;
+use log::{error, info};
 use tokio::sync::oneshot::{Receiver, Sender};
 
 use super::routes::router;
@@ -102,7 +102,6 @@ impl ApiServer<Stopped> {
             launcher
         });
 
-        //let address = rx_start.await.expect("unable to start service").address;
         let api_server = match rx_start.await {
             Ok(started) => ApiServer {
                 state: Running {
@@ -112,7 +111,7 @@ impl ApiServer<Stopped> {
                 },
             },
             Err(err) => {
-                let msg = format!("unable to start API server: {err}");
+                let msg = format!("Unable to start API server: {err}");
                 error!("{}", msg);
                 panic!("{}", msg);
             }
@@ -170,29 +169,32 @@ impl Launcher {
         tokio::task::spawn(graceful_shutdown(
             handle.clone(),
             rx_halt,
-            format!("Shutting down http server on socket address: {address}"),
+            format!("Shutting down tracker API server on socket address: {address}"),
         ));
 
         let tls = self.tls.clone();
+        let protocol = if tls.is_some() { "https" } else { "http" };
 
         let running = Box::pin(async {
             match tls {
                 Some(tls) => axum_server::from_tcp_rustls(socket, tls)
                     .handle(handle)
                     .serve(router.into_make_service_with_connect_info::<std::net::SocketAddr>())
                     .await
-                    .expect("Axum server crashed."),
+                    .expect("Axum server for tracker API crashed."),
                 None => axum_server::from_tcp(socket)
                     .handle(handle)
                     .serve(router.into_make_service_with_connect_info::<std::net::SocketAddr>())
                     .await
-                    .expect("Axum server crashed."),
+                    .expect("Axum server for tracker API crashed."),
             }
         });
 
+        info!(target: "API", "API server started on {protocol}://{}", address);
+
         tx_start
             .send(Started { address })
-            .expect("the HTTP(s) Tracker service should not be dropped");
+            .expect("the HTTP(s) Tracker API service should not be dropped");
 
         running
     }