Introduce ArFrameMetadata to relly less on virtual functions for metadata getters

openVulkanoCpp/AR/ArFrame.cpp

@@ -0,0 +1,16 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+#include "ArFrame.h"
+#include "ArSession.h"
+
+namespace openVulkanoCpp::AR
+{
+	float ArFrame::GetConfidenceNormalisationFactor() const
+	{
+		return session->GetSessionMetadata().GetConfidenceNormalisationFactor();
+	}
+}