Fix: Product sale report would mix different product versions as it was checking the product id and not version id

Feature: Cannot add na product to bill

bookie/src/app/sales/products/products.component.ts

@@ -22,6 +22,9 @@ export class ProductsComponent implements OnInit {
   }
 
   addProduct(product: Product): void {
+    if (product.isNotAvailable) {
+      return;
+    }
     this.bs.addProduct(product, 1, 0);
   }
 }