[MISC] LanguagePreference material proxy from Alien Swarm: Reactive Drop

[Blixibon]

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

Currently, localization packages which need to change textures must override the files themselves. This makes them incompatible with existing content/other languages.

Describe the solution you'd like

Alien Swarm: Reactive Drop has a material proxy to change parameters based on the currently selected language:
ReactiveDrop/reactivedrop_public_src@ea168e0

Describe alternatives you've considered

For Steam games, textures in other languages can be included as separate packages automatically downloaded by players who are using the language on Steam. This may be a better solution for developers who can use it, but may also be a pain to maintain.