Add .OBJ loader

[magarcan]

Just found this branch exists. I've my own .OBJ loader implementation (no materials support, just diffuse).
I think would be amazing to have this function implemented in Vanilla GRRLIB.

Do you have any plan to implement it?

Thanks!!!

[Crayon2000]

I have "rebased" the 3D_test branch onto the master branch. It should now work like it did 10 years ago.

As of now, I have no plans to implement it.

I could take a look at it if I feel like it. No promises 😊