Introduce method-level caching for department reports to enhance performance

- Wrap report calculation logic in `methodCacheWithParameters` for 2-minute caching.
- Standardize reusable caching logic in `db_object_t` trait.
- Refactor query-based methods to integrate caching and improve maintainability.

services/nginx/app/classes/redis.php

@@ -397,5 +397,4 @@ class redis implements redis_i
         // Get multiple keys from Redis
         return $this->redis->mget($array_map);
     }
-
 }