Enhancement: Support for multiple sentences.txt

[JJL772]

What would this enhancement be for?

Audio

Describe your enhancement suggestion in more detail

Currently the VOX subsystem can only load a single sentences.txt, which makes it impossible to grab sentences from mounted mods. In the case of mounted steam games, it's probably not desirable to pick up every sentences.txt, but for workshop addons we probably want to allow this. Might also make organization of the scripts folder a bit easier.

This feature is more for p2ce but it does affect the entire engine.