add get-breadcrumb endpoint

app/utils/const_data/consts.go

@@ -3,6 +3,11 @@ package constdata
 // PASSWORD_VALIDATION_REGEX is used by the frontend (JavaScript supports lookaheads).
 const PASSWORD_VALIDATION_REGEX = `^(?=.*[a-z])(?=.*[A-Z])(?=.*\d).{10,}$`
 const SHOP_ID = 1
+const SHOP_DEFAULT_LANGUAGE = 1
+
+// CATEGORY_TREE_ROOT_ID corresponds to id_category in ps_category which has is_root_category=1
+const CATEGORY_TREE_ROOT_ID = 2
+
 const MAX_AMOUNT_OF_CARTS_PER_USER = 10
 const DEFAULT_NEW_CART_NAME = "new cart"