OpenVR SDK 2.12

• Add struct VREyeTrackingData_t, used with CreateEyeTrackingComponent, and UpdateEyeTrackingComponent for drivers to provide eye tracking input to SteamVR.
• Synchronize props to upstream SteamVR.
• Testing with GetSubmitTexture - Do not use - this feature will likely be removed.
• NewSharedVulkanSemaphore signature is now different, allowing for a counting semaphore.
• Added properties used internal to SteamVR, and OpenXR
• Added preprocessor option for OPENVR_NO_STL
• Added property for disabling/enabling keyboard privacy
• Added driver feature to allow HMD or SteamVR to control texture index and application poses. For HMD Drivers. We recommend display drivers update to the new default behavior, allowing SteamVR to control the texture index, and automatically compositing multiple layers into the system layer
• Add VROverlayFlags_MinimalControlBar
• Add PollNextEventWithPoseAndOverlays to IVRSystem to allow overlay applications to poll all events associated with any overlay it's created. This is equivalent to calling PollNextOverlayEvent for each of your overlays as well as PollNextEvent
• Added CreatePoseComponent and UpdatePoseComponent to IVRDriverInput