Add/Fix VR Controller Input

VR controller input doesn't work astoundingly well through older versions of VTK. It reports some buttons with ids but not all work. Mostly just the triggers. With VTK 9.1 comes the introduction of json input files for mapping actions which is useful here. Eventually it'd be nice to have a more generic interface. But for now, this issue is just about getting the other buttons and thumbstick/trackpad of the controllers working.