Some nicer terrain while we wait on vanilla terrain gen

[ReCore-sys]

This PR adds in the terrain generation system I was messing around with months ago. It' not particularly good or fast, but it's a lot nicer than the boring perlin noise terrain we currently have.

Description

This PR adds a more complex but still temporary terrain gen system. It uses some techniques like noise blending and some simple biomes. It also has some major upsides such as being complicated enough to expose issues with the chunk system and similar, making it much easier to fix.

Motivation and Context

The perlin noise terrain is pretty boring and this at least gives us something more interesting to look at until @Mcrtin finishes the vanilla terrain gen. It also makes it much easier to find bugs in the chunk logic since the perlin noise terrain just isn't complex enough to trigger it.

How has this been tested?

Idk the terrain doesn't look quite as ass any more?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Refactor (restructuring code, without changing its behavior)

Checklist:

• My code follows the code style of this project.
• I have added tests to cover my changes.
• All new and existing tests passed.
• Clippy passes with no warnings.

[Sweattypalms]

merge after fixing conflicts?

[ReCore-sys]

merge after fixing conflicts?

Currently chunk sending is broken so probably once I have that fixed.