Magic button that solves everything in the database

[monsieurtanuki]

Problem

As evoked in #2255, there are at least two sentry issues related to probable database inconsistencies (like a product list whose products are not in the product database):

• https://sentry.io/organizations/openfoodfacts/issues/3329300698/?project=5376745&query=is%3Aunresolved
• https://sentry.io/organizations/openfoodfacts/issues/3377849466/?project=5376745&query=is%3Aunresolved

A typical log would display something like unexpected: unknown product for 3760091725769

Proposed solution

At app startup, we could run a database check and - if needed - solve the database inconsistencies (which means product downloads). We would display a "Oops" dialog with a "fix now!" button.

Additional context

Based on the same idea, we could check the local freshness of the products and suggest a refresh.

Part of

• _CastError: Null check operator used on a null value #2255

[VaiTon]

I propose doing that in a background thread and if needed block the user with a "Updading database version..." dialog, so that it doesn't seem like the app db is sometimes a mess (although it can be)

[monsieurtanuki]

@VaiTon Actually it's not that messy, it's just a minor inconsistency. And from #2673 it's dealt with automatically when a product is displayed in a list.
We'll see how often we have issues like that.