On the main page (/), we fetch prices and order them by `-created`

[raphael0202]

The following request is sent:

https://prices.openfoodfacts.org/api/v1/prices?app_name=Open+Prices+Web+App&page=1&size=25&order_by=-created

There is no index on created, so this request is slow. We should order by -id instead.

[raphodn]

It would be more "user intuitive" to keep the current default order (in any case, it's available as one of the possible ordering options).

And rather add indexing/optimizations in the backend.

Id is kinda a "internal" logic