Templates and TLS requests

Refactored HTML templates and added TLS back to issue HTTP requests

src/routes/admin/newsletters.rs

@@ -127,7 +127,7 @@ pub async fn publish_newsletter(
         .context("Failed to enqueue delivery tasks.")?;
 
     let message = String::from("Your email has been queued for delivery.");
-    let template = MessageTemplate::Success { message };
+    let template = MessageTemplate::success(message);
     let response = Html(template.render().unwrap()).into_response();
     let response = save_response(transaction, &idempotency_key, user_id, response)
         .await