* Move client interpolation pump to earlier in the iteration before 3D physics synced
* Allow `get_global_transform_interpolated()` to prime the client interpolation inside a physics tick
* Moves 3D Camera interpolation scene side.
* Automatically switches `get_camera_transform()` to report interpolated transform during `_process()`.
* Fixes `ClippedCamera` to work with physics interpolation.
Add scene side discrete level of detail.
New node `LOD` for UI, and `LODManager` within `World` for automatically updating child visibilities based on distance from cameras.
