Serialization of CityObjects into GeoDB

Summary

Implementing serialization of CityObjects to a GeoDB.

What is the function?

Allowing CityObjects to be saved to/loaded from a GeoDB.

Why is it requested?

Enables harddrive memory paging of CityObjects, greatly reducing RAM usage of CityDoctor and thus allowing handling of bigger CityGML files.

Would unify the stream and in memory validation functions, simplifying the code.

Required for the implementation of topological checks.

Spatial functions like ST_Intersects allow pre-filtering of CityObjects and simplify the implementation of some functions.

Enables implementation of an internal tiling system for the rendering of bigger CityGML files.