GeometryCollectionComponents that have root proxies will now create root proxy static mesh components when there is no other render method enabled.

This deals with an edge case with geometry collection custom renderers. Custom renderers don't run in edition mode, and in editor we would expect to have mesh data available instead. But for UEFN editor with cooked data, the mesh data may already be removed (because it is not needed in cooked game).
#rb Shaun.Kime
[FYI] cedric.caillaud

[CL 31643010 by jeremy moore in ue5-main branch]

Engine/Source/Runtime/Experimental/GeometryCollectionEngine/Public/GeometryCollection/GeometryCollectionComponent.h

@@ -1825,6 +1825,12 @@ private:
 
 	void UpdateBrokenAndDecayedStates();
 
+	bool ShouldCreateRootProxyComponents() const;
+	void CreateRootProxyComponentsIfNeeded();
+	void ClearRootProxyComponents();
+
+	TArray<TObjectPtr<UStaticMeshComponent>> RootProxyStaticMeshComponents;
+
 private:
 
 	enum class ENetAwakeningMode