Get products in a category (uses the search engine)
Get ALL categories for the market (flat list; build the tree from parentId).
Pages through /categories?page&limit so large trees are never truncated.
Against an older API that ignores the paging params (and answers with a plain
array), the array is returned as-is.
Optionallocale: stringOne page of categories: { categories, pagination } (limit max 250).
Get a single category by URL handle