- Add Redis mget method and cache management improvements

- Update cache expiration times for `economicCustomerName` and `isBooked` objects
- Introduce `getCachedForMultipleObjects` for batch cache retrieval
- Optimize `isBooked` with optional caching and update to store results
- Implement `getCustomerNames` in `users_o` with caching for bulk name retrieval
- Refactor customer transaction handling in `InvoicingPeriodRoute` for efficiency
- Filter orders excluded from invoicing in `collected_order_invoices_o`

services/nginx/app/classes/redis.php

@@ -392,4 +392,10 @@ class redis implements redis_i
         return 'temporary_cache_' . uniqid();
     }
 
+    public function mget(array $array_map): array
+    {
+        // Get multiple keys from Redis
+        return $this->redis->mget($array_map);
+    }
+
 }