Hook up the visibility property to the active flag

We may want more fine-grained control over visibilty later, but for now
let's assume that a non-visible nodes are inactive nodes.

src/quick3d/qdemonnode.cpp

@@ -242,6 +242,8 @@ QDemonRenderGraphObject *QDemonNode::updateSpatialNode(QDemonRenderGraphObject *
     else
         spacialNode->markDirty(QDemonRenderNode::TransformDirtyFlag::TransformNotDirty);
 
+    spacialNode->flags.setFlag(QDemonRenderNode::Flag::Active, m_visible);
+
     return spacialNode;
 }