Proper handling of UI languages

[kelson42]

Kiwix is now able to handle many languages and the syncrhonisation with Translatewiki has been achieved. But it is still important that the "correct" language is chosen to display the UI:

• Custom apps
  • enforced_lang lang is specified in the info.json
    • UI language should not be customizable (in the OS - but app related - settings)
    • UI language should be the one specified in info.json
  • Otherwise works like the Kiwix app
• Kiwix app
  • UI languages should be configurable (in the OS - but app related - settings) on iOS (but nothing for the moment on macOS, see Allow to change the UI language via a setting on macOS #604)
  • Default language should be the one of the OS

This is valid for iOS and macOS.

[kelson42]

@BPerlakiH Do you confirm this is clear? This makes sense? Does it already works like this?

[rgaudin]

there is no such thing as app préf in OS for macOS. It's only iOS

[kelson42]

there is no such thing as app préf in OS for macOS. It's only iOS

Then, no way to configure the UI language for the moment. I have open an other ticket for this enhancement (not a priority for the moment).

[BPerlakiH]

Thank you @kelson42 it makes sense.
This really means we should include only the enforced language in the custom app.
I will reflect these changes in the latest release.

[BPerlakiH]

I've created the releases for DWDS app 2023.12.3 (build 133) to reflect these changes, and created a PR to revert the unnecessary changes in the main repo: #605

The project level (automatic) handling of the enforced language will be included on the kiwix-apple-custom repo side.