Price tags: levels of difficulty (ex: AI found an existing product or category)

[raphodn]

Story

Currently, all the Price Tags (with status=None) are visible in the Price Validation Assistant (web frontend).
But some PT are very hard to decipher, or simply not well detected. And we have new users who find the PVA too complex.

In order to build a simplified PVA, we need to isolate simple PTs from difficult ones.

How

An idea is to sort them by magnitudes of difficulties :

• level 1 : found a barcode corresponding to an existing product
• level 2 : found an existing category
• level 3 : found a valid barcode, but no product exists yet
• level 4 : the rest 😅

We could add a field difficulty_level that would be calculated similarly to #656

The tricky bit is that this field would be stored on the prediction. So we then need to be able to filter the API on the predictions...