Fix Vive controller bindings on OpenXR

[ada-tv]

The thumbstick emulation thing I added in #1948 was apparently broken. This gets Vive controllers working again and gives them access to the primary button by clicking the center of the trackpad.

[SuperPou1]

works for me

[JulianGro]

Are the triggers on the Vive Wands triggered too easily? Or is this unrelated?

At least on my Oculus Quest 1, the change isn't noticeable. I would be more worried about the Vale Index controllers anyway though.

[ada-tv]

This change is so the virtual "click" action is triggered a little before the trigger bottoms out against the physical click button on the Vive controllers. Index controllers hit 1.0 a bit before bottoming out, but Vive controllers bottom out around 0.7-0.8.

[JulianGro]

I guess at some point we would want to be able to set different mappings for different controllers.

Though I already see how vaguely the controllers are identified by some runtimes:

LOG in xrGetSystem: Selected devices
	Head: 'WiVRn HMD'
	Eyes: '<none>'
	Left: 'WiVRn left controller'
	Right: 'WiVRn right controller'
	Gamepad: '<none>'
	Hand-Tracking Left (unobstructed): 'WiVRn left controller'
	Hand-Tracking Right (unobstructed): 'WiVRn right controller'
	Hand-Tracking Left (conforming): '<none>'
	Hand-Tracking Right (conforming): '<none>'
[08/10 17:30:04] [INFO] [openxr.context] System name         : Oculus Quest on WiVRn
[08/10 17:30:04] [INFO] [openxr.context] Max layers          : 128
[08/10 17:30:04] [INFO] [openxr.context] Max swapchain size  : 16384x16384
[08/10 17:30:04] [INFO] [openxr.context] Orientation Tracking: 1
[08/10 17:30:04] [INFO] [openxr.context] Position Tracking   : 1

I haven't tested this on the Valve Index's controllers, but it should be good enough, I guess.