feat: refactor product attributes caching logic and add HashArray utility function

internal/wb/products/repository_api.go

@@ -95,7 +95,8 @@ func fetchProducts(
 }
 
 func (a apiRepository) StreamAllProductsCache(ctx context.Context, marketplaceId int, resultChan chan<- []pb.Product, errChan chan<- error) {
-	// DO NOT close channels here - WithCache will handle it (caller/creator owns them)
+	defer close(resultChan)
+	defer close(errChan)
 	mp, err := a.marketplaceRepository.GetMarketplaceByID(ctx, marketplaceId)
 	if err != nil {
 		errChan <- fmt.Errorf("getting marketplace by ID: %w", err)