Loading performance: Disable Mesh + VOBs during loading

[JaXt0r]

Description

When we currently load the game, all meshes of world and VOBs will be loaded fully and disabled once culling kicks in, which is after everything is loaded. On VR devices loading starts to stutter more and more over time. Therefore let's disable all meshes/GOs once they're loaded immediately to save performance during loading.

Tasks

• [ ] World + VOBs - Once object is loaded, call .SetActive(false)
• [ ] Once everything is loaded and normal Culling kicks in (e.g. VobMeshCulling) we might need to do an initial .Query() to re-enable elements next to us. (Based on experience, culling won't trigger an initial "visible" Event)

[ThomasMountainborn]

We also need to remove the old texture arrays before starting to load the textures of the new world to avoid going out of memory on device.