Split octree file format in some way to allow for better error handling

[NotStirred]

Currently if anything in octree loading has any error the state of everything is unknown, and any data that hasn't yet been loaded is completely lost

Perhaps just having a different data stream for every major thing, combined later would solve this.

It concerns me that a single error in any part of loading makes the entire thing unloadable (particularly because I've just edited it in #1225 🤣)

[MadDog443]

This would save me hours considering I've done a few mega renders that go over 300k chunks. When it comes across an error and I have to start over again it can take up a lot of time going through trial and error.

[NotStirred]

Sorry, by "Octree Loading" I'm referring to loading from save, not loading new chunks into an octree

[MadDog443]

Sorry, by "Octree Loading" I'm referring to loading from save, not loading new chunks into an octree

Damn. This is a sad day. Still handy though.