Add OpenVR notification support to C# header file

openvr_api_patch.diff

diff --git a/SteamVR_HUDCenter/SteamVR/openvr_api.cs b/SteamVR_HUDCenter/SteamVR/openvr_api.cs
index 37ee80a..5316fc3 100644
--- a/SteamVR_HUDCenter/SteamVR/openvr_api.cs
+++ b/SteamVR_HUDCenter/SteamVR/openvr_api.cs
@@ -5631,6 +5631,7 @@ public enum EIOBufferMode
        public IntPtr m_pVRInput; // class vr::IVRInput *
        public IntPtr m_pVRIOBuffer; // class vr::IVRIOBuffer *
        public IntPtr m_pVRSpatialAnchors; // class vr::IVRSpatialAnchors *
+       public IntPtr m_pVRNotifications; // class vr::IVRNotifications *
 }

 public class OpenVR
@@ -5948,6 +5949,7 @@ public class OpenVR
                m_pVRTrackedCamera = null;
                m_pVRInput = null;
                m_pVRSpatialAnchors = null;
+               m_pVRNotifications = null;
            }

            void CheckClear()
@@ -6128,7 +6130,20 @@ public class OpenVR
                return m_pVRSpatialAnchors;
            }

+           public CVRNotifications VRNotifications()
+           {
+               CheckClear();
+               if (m_pVRNotifications == null)
+               {
+                   var eError = EVRInitError.None;
+                   var pInterface = OpenVRInterop.GetGenericInterface(FnTable_Prefix + IVRNotifications_Version, ref eError);
+                   if (pInterface != IntPtr.Zero && eError == EVRInitError.None)
+                       m_pVRNotifications = new CVRNotifications(pInterface);
+               }
+               return m_pVRNotifications;
+           }
+
            private CVRSystem m_pVRSystem;
            private CVRChaperone m_pVRChaperone;
            private CVRChaperoneSetup m_pVRChaperoneSetup;
@@ -6141,6 +6156,7 @@ public class OpenVR
            private CVRTrackedCamera m_pVRTrackedCamera;
            private CVRInput m_pVRInput;
            private CVRSpatialAnchors m_pVRSpatialAnchors;
+           private CVRNotifications m_pVRNotifications;
        };

        private static COpenVRContext _OpenVRInternal_ModuleContext = null;