I want gz::sim::SdfEntityCreator to support creating ECS entities from SDF projectors.

I want gz::sim::SdfEntityCreator to support creating ECS entities from SDF projectors.: a task in MiMo-V2.6-RL-oss: Agentic RL Environments (MiMo RL release). I want gz::sim::SdfEntityCreator to support creating ECS entities from SDF projectors. Given an existing SdfEntityCreator, calling Entity…