Allow sorting latest prices reverse chronologically, or filter per year

[teolemon]

Problem

• We now have cool price points from 2010.
• I'd like us to surface them (that's a unique selling point)

Possible solutions

• Allow sorting latest prices reverse chronologically, or filter per year
• create a price-added/2010-02 facet

Part of

• 220

[raphodn]

Started working on this :

• added a backend price filter by date year & month : https://github.com/openfoodfacts/open-prices/pull/350
• added a frontend page per date /dates/YYYY-MM-DD

Next up :

• a frontend page per month : /dates/YYYY-MM
• a fronend page per year : /dates/YYYY

[raphodn]

Deploying ! Not yet findable for end users, but the urls above show the prices for a given date / month / year

[raphodn]

made some changes in #687 to better display the price date. the user can click on the chip to access the prices for the given date