Adds scene saving and loading functionality, using a component factory for dynamic component creation and serialization.
This allows users to save and load the state of entities, including their components and textures.
A new component factory is introduced to register and create different component types.
Each component implements serialization and deserialization methods, which are used to store and restore the component's state.
A new .ker scene file format is introduced to serialize entity data and to load it back into memory to restore the scene.
Also adds a DemoScene_V12.9.0.ker file to showcase the engine.
