Provide a setting to use pseudo localization

[ccjmk]

Is your feature request related to a problem? Please describe.

Following our discussion on discord, I leave this here so it doesn't get lost on the woods. The problem arised from a wiki recommendation to reuse existing i18n flags as much as possible, without any particular warning about cases where that might not be suitable. In my particular case, I had use-cases from the Japanese community and the Italian translation, where reusing keys would have prevented them from localizing some strings in a manner that worked for the UI in their respective languages.

That conversation lead to this article which showcases an interesting dev approach by Netflix for localizations: https://www.techinasia.com/talk/pseudo-localization-netflix

Describe the solution you'd like

A string setting where localization prefixes can be listed (separated by commas or semicolons maybe), and any localization matching that prefix gets pseudolocalized instead (to prevent doing this app-wide)

Describe alternatives you've considered

If it were possible to detect where the localizations are coming from, maybe use flags instead, to only pseudolocalize handpicked modules. (haven't dived much into this to tell at the moment)