Templates and TLS requests

Refactored HTML templates and added TLS back to issue HTTP requests

src/routes/admin/change_password.rs

@@ -49,9 +49,7 @@ pub async fn change_password(
         authentication::change_password(user_id, form.new_password, &connection_pool)
             .await
             .map_err(AdminError::ChangePassword)?;
-        let template = MessageTemplate::Success {
-            message: "Your password has been changed.".to_string(),
-        };
+        let template = MessageTemplate::success("Your password has been changed.".to_string());
         Ok(Html(template.render().unwrap()).into_response())
     }
 }