remove generator script load_structures function

src/world/generator/GeneratorDef.hpp

@@ -123,9 +123,6 @@ class GeneratorScript {
 public:
     virtual ~GeneratorScript() = default;
 
-    /// @brief Load all structures
-    virtual std::vector<std::shared_ptr<VoxelFragment>> loadStructures() = 0;
-
     /// @brief Generates a heightmap with values in range 0..1
     /// @param offset position of the heightmap in the world
     /// @param size size of the heightmap