feat: 3719 - new "scan history" page among the account product lists

[monsieurtanuki]

What

• There is a "scan session" page, typically for recently scanned products.
• But there was no huge "scan history" page, with all the previously scanned products.
• Now this list does exist. It's populated at the same time as "scan session", but is not cleared when "scan session" is cleared. This list is accessed from the account page - that can be changed if needed.

Screenshot

cf. "Scan History / 3"

Fixes bug(s)

• Closes: Add a permanent scan history #3719

Impacted files

• app_en.arb: added 1 label for "scan history"
• continuous_scan_model.dart: added the product to "scan history"
• product_list.dart: added "scan history"; refactored ProductListType
• product_list_page.dart: added "scan history"
• product_query_page_helper.dart: added "scan history"
• user_preferences_account.dart: added an access to the "scan history" page

[teolemon]

How about putting it among lists ?

[monsieurtanuki]

How about putting it among lists ?

There are "account product lists" (e.g. "products I edited (at the server level)") and "user product lists" (e.g. local custom "My breakfast cereals"). And "history" and "scan session" are away from both, and accessed via specific actions.
In this PR, I added the new "scan history" to "account product lists", which is not very consistent.
If we move it to "user product lists", it's not very consistent either, and there's not the "custom" effect like "you have no lists for the moment: create your first list!".
Possibly we can create a dedicated access to a new concept of "automatic lists": "history", "scan session" and "scan history". Not sure it would be clearer for the end user.

[teolemon]

Ok, my brain melted one hour ago, but:

• What about bringing the lists shortcut closer to the current History tab.
• How about allowing to switch between History and User Lists in the Top Bar (with a dropdown on the top bar title ?). The idea is that History and Scan History are just some more lists.
  @monsieurtanuki @M123-dev @g123k

[teolemon]

Thanks @monsieurtanuki
Approving

[monsieurtanuki]

Thank you @teolemon for your review.

Your suggestion about refactoring the concept of lists from the user's perspective is interesting and deserves its own issue.