[SFM/DL] Refract Lenses

Someone from PonySFM Discord server was asking for it and I had that thing being used for over a year now, so there you go. :]

What this is?
Pretty much invisible model with visible cubemaps. This should help to imitate Refract eyes shader.
Additional bodygroup will allow to switch between default Refract cubemap (the one you can find on pony models using that shader) and map cubemap (using same cubemap as area of map model is placed).

What's the point of it? Why not just use Refract shader?
Well, here's why. Refract shader requires different values for eyes position in QC files than those used on normal version of eyes, which means that you will need to have 2 versions of each model prepared if you want to switch between those two options. Also, trick with uberlight (making eyes glow in dark) doesn't work on Refract shader, which limits it's potential in some situations. This simple model should fix those issues. At least mostly.

Important stuff:
    - For now only female, male and alt_male v5 models are supported. I will add more lenses later if needed.
    - This is not 100% accurate when compared to Refract shader due to engine limitations.
    - If second bodygroup (map cubemap, a.k.a envmap) is not visible, that doesn't mean it's broken. Turn off lights and turn them back on and model should appear. If not, that means map doesn't use cubemaps or there is no cubemaps in this are, so bodygroup will not work.
    - If you want to replace cubemap to something premade, just use materials override in the same way you change $basetexture, except now you type $envmap in it's place.

Also:
    - Model is already part of NexGen SFM Model Pack and you don't need to download it if you're focusing on anthro art.
    - You don't need to replace any files if notification will appear during archive extraction.

I would ask to not re-upload model to any other sites, but judging how it went with RD model, it's not really important.