VR Expansion Plugin

I have an experimental branch up where I have been thinking about the best way to make the car seat setup a native part of the VRBaseCharacter and implement it cleanly and correctly over the network. It has accumulated several changes besides that from me fixing / changing things as I go, so if I don’t finish the seating part before the holiday I will likely strip those out separately and push them live.

The most notable change is stripping out all reliance on the VRExp module from the OpenVR module so that it can be used by itself (no more tracked device requirement so I can finally do ). happens to be just in time for 4.19 bringing in true model loading for VR tracked devices natively built into the engine ;p so I will at some point be removing the code for loading the SteamVR models as well when their implementation proves stable.

Just wanted to give a heads up why no commits were happening lately.