Initial VR Support

I fixed VR rendering, since starting the project we had worked a lot on improving some rendering flexibilities for Source 2 and adapting it to work for what we want but never validated for VR until now.

Getting VR in a good state has always been a concern for us and I'm glad now that I've tackled the initial work to have it supported.

This was just the first step, not much is bound to the actual s&box code yet, so right now the only thing you can do is being a passive tourist in your creations, but this opens the door for us to experiment with it and build something that everyone could enjoy and build upon.