Add Localization Support to the Inno Setup Installer

[Dimi20cen]

Current behavior

The new Inno Setup installer, introduced in PR #170, currently only supports English. This is a regression from our legacy installer, which supported multiple languages.

Desired behavior

We should externalize all user-facing strings from the kolibri.iss script into separate language files (.isl). This will allow translators to work on language files without touching the core installer logic and enable users to select their preferred language when the installer starts.