feat(BE): refactor search queries to be case insensitive across all modules

internal/modules/inventory/product-warehouses/repositories/product_warehouse.repository.go

@@ -399,11 +399,11 @@ func (r *ProductWarehouseRepositoryImpl) ListProductIDsByFlagPrefixes(ctx contex
 		}
 		like := prefix + "%"
 		if !applied {
-			db = db.Where("flags.name LIKE ?", like)
+			db = db.Where("LOWER(flags.name) LIKE LOWER(?)", like)
 			applied = true
 			continue
 		}
-		db = db.Or("flags.name LIKE ?", like)
+		db = db.Or("LOWER(flags.name) LIKE LOWER(?)", like)
 	}
 
 	if visibleStatus != nil {