`GetPrimitiveFeatures` doesn't work for instanced tilesets

[j9liu]

What happened?

GetPrimitiveFeatures returns an empty primitive features for instanced tilesets. This is because of these lines of code:

cesium-unreal/Source/CesiumRuntime/Private/CesiumPrimitiveFeatures.cpp

Lines 45 to 51 in 1e9f442

	UCesiumPrimitiveFeaturesBlueprintLibrary::GetPrimitiveFeatures(
	const UPrimitiveComponent* component) {
	const UCesiumGltfPrimitiveComponent* pGltfComponent =
	Cast<UCesiumGltfPrimitiveComponent>(component);
	if (!IsValid(pGltfComponent)) {
	return EmptyPrimitiveFeatures;
	}

It should also be checking for an UCesiumGltfInstancedComponent, and returning the attached features if found.

Environment

Cesium for Unreal version: v2.16.1
Unreal Engine Version: 5.4
Operating System: Windows

Reproduction steps

1. Open the sample level 06_CesiumMetadata.
2. Load the Instanced Orientation tileset from URL.
3. In the Level Blueprint, recreate this Blueprint:
4. Run the level. Click on any of the cubes. You should see a -1 printed no matter what cube you press. However, the metadata table will be populated with the Height property.