SteamVR plugin Part1
A functional SteamVR plugin that supports distortion correction, angled/canted displays (from get_view_pose), and controller input for Index, Vive and Playstation Move controllers. In this MR all controllers emulate an Index controller, i.e. use the input profile and render models distributed by SteamVR.
In follow up MRs we will generate input profiles from Monado's bindings.
Unfortunately a6913fe0 grew quite big during rebase. We can split out at least the sdl2_hack changes if it's worth it.