feat: create a server function for getting the language identifier

src/server/internationalization.rs

@@ -0,0 +1,14 @@
+use std::env;
+use dioxus::prelude::ServerFnError;
+use unic_langid_impl::LanguageIdentifier;
+use dioxus::prelude::*;
+use dotenvy::dotenv;
+
+#[server]
+pub(crate) async fn get_language_identifier() -> Result<LanguageIdentifier, ServerFnError> {
+    dotenv().expect("Could not load environment variables from the .env file.");
+    
+    Ok(env::var("LANGUAGE_CODE")
+        .expect("The environment variable LANGUAGE_CODE must be set.")
+        .parse::<LanguageIdentifier>()?)
+}

src/server/mod.rs

@@ -2,3 +2,4 @@ mod database_connection;
 pub(crate) mod projects;
 pub(crate) mod tasks;
 pub(crate) mod subtasks;
+pub(crate) mod internationalization;