Clarify or break down some background tasks into more granular tasks

[teolemon]

To reduce potential for errors, and add resiliency, we should consider breaking down some background tasks into more granular tasks

• Currently, we have one single task for language refresh after language change. Having the progress in terms of products refreshed, or one task per product to refresh ?
• Currently, we have one single task for offline mode download, with little visibility on the progress (ideally, 2345/10000 products available for offline use)
• Other tasks ?
  Originally posted by @teolemon in feat: 5689 - separate tasks (proof upload and prices adding) #6781 (review)

[monsieurtanuki]

@teolemon In both cases your assumption is incorrect: there are several background tasks with a progress for language refresh and offline download.
Even if we wanted we couldn't download more than 100 products at a time, as a server limit.
We currently download products by pages of 20 products for language refresh, and 100 products for offline.