CesiumGS/cesium-unreal

AI Summary: The task requires modifying the Cesium for Unreal plugin's `GetPrimitiveFeatures` function to correctly handle instanced tilesets. Currently, it returns empty features for these tilesets because it doesn't check for `UCesiumGltfInstancedComponent`. The fix involves adding a check for this component and returning the attached features if found. This will ensure that metadata, such as the 'Height' property in the provided example, is correctly retrieved for instanced tiles.