Emscripten translation feature: localised text files do not load for Control String Variables without preloading

[Mimigris]

Player platform:
Webplayer, latest version of the Player.

Describe the issue in detail and how to reproduce it:
On the webplayer, if in a game with Maniac patch enabled, you attempt to load a text file using Control String Variables, the file will properly be loaded. Thing is, if you have a translation active, and the text file has an existing translation for said language, the translated text file will not be loaded and the original text file will be loaded instead.
Interestingly enough though, the translated text file is able to be loaded without issues with the translation feature, granted that it has been loaded at least once during the session (e.g. if you have a text file hello.txt in the Text folder, and one in Language/fr/Text for the French language, loading ../Language/fr/Text/hello.txt while make it so that upcoming calls of the hello.txt file while using the French translation will correction call the localised asset).

[Ghabry]

Best approach is likely to invent a new "version 3" index.json format which does not strip of the extensions anymore (this is the problem now that reading of arbitrary (text) files is possible) and move the file extension testing for the index file into the Player.