Extract modules declaration from main.rs to lib.rs in "hagrid" crate.

This is to make "hagrid" code library alike instead of having it as a binary
which improves reusability and testability of the code.

So, the main.rs binary will be just a launcher for library code.

Changes:
- Extract modules declaration from main.rs to lib.rs in "hagrid" crate.
- Introduce "app" module which has to accumulate infrustructure code,
  but for the time being it delegates run() and handle errors.
- Rename hagrid::web::serve() to hagrid::web::run() to standardize on
  module entry function names.
- Accumulate rocket framework launching code in hagrid::web::run()
  function.
  To be able to move code around I have to replace usage of
  macros like #[rocket::launch] or #[rocket::main] with direct usage of
  :🚀:async_main, ignite() and launch() functions.

src/app/mod.rs

@@ -0,0 +1,3 @@
+pub fn run() {
+    crate::web::run().unwrap_or_else(|e| eprintln!("Hagrid Error: {e}"))
+}

src/lib.rs

@@ -0,0 +1,25 @@
+#![recursion_limit = "1024"]
+
+use gettext_macros::init_i18n;
+
+mod anonymize_utils;
+pub mod app;
+mod counters;
+mod dump;
+mod gettext_strings;
+mod i18n;
+mod i18n_helpers;
+mod mail;
+mod rate_limiter;
+mod sealed_state;
+mod template_helpers;
+mod tokens;
+mod web;
+
+#[cfg(debug_assertions)]
+init_i18n!("hagrid", en, de, ja);
+
+#[cfg(not(debug_assertions))]
+init_i18n!(
+    "hagrid", en, de, fr, it, ja, nb, pl, tr, zh_Hans, ko, nl, ru, ar, sv, es, ro
+);

src/main.rs

@@ -1,30 +1,3 @@
-#![recursion_limit = "1024"]
-
-use gettext_macros::init_i18n;
-use rocket::launch;
-
-#[cfg(debug_assertions)]
-init_i18n!("hagrid", en, de, ja);
-
-#[cfg(not(debug_assertions))]
-init_i18n!(
-    "hagrid", en, de, fr, it, ja, nb, pl, tr, zh_Hans, ko, nl, ru, ar, sv, es, ro
-);
-
-mod anonymize_utils;
-mod counters;
-mod dump;
-mod gettext_strings;
-mod i18n;
-mod i18n_helpers;
-mod mail;
-mod rate_limiter;
-mod sealed_state;
-mod template_helpers;
-mod tokens;
-mod web;
-
-#[launch]
-fn rocket() -> _ {
-    web::serve().expect("Rocket config must succeed")
+fn main() {
+    hagrid::app::run()
 }

src/web/mod.rs

@@ -391,8 +391,14 @@ fn errors(
     Ok(Custom(status_code, response_body))
 }
 
-pub fn serve() -> anyhow::Result<rocket::Rocket<rocket::Build>> {
-    rocket_factory(rocket::build())
+pub fn run() -> Result<(), rocket::Error> {
+    let rocket = rocket_factory(rocket::build()).expect("Rocket config must succeed");
+
+    ::rocket::async_main(async move {
+        let _rocket = rocket.ignite().await?.launch().await?;
+
+        Ok(())
+    })
 }
 
 compile_i18n!();