TerraformGenerator

Heavy optimisations done, there should be a noticeable difference in speed.

• Large structural changes, mainly focused around TerraformGenerator.generateNoise and HeightMap
• Ripped out Guava's cache, as a much weaker guarantee can be used (all the writers write the same thing, so coherence is way less of a problem)
• Blurring is now cached in the BiomeSection level to avoid competing ChunkCache writes
• Introduced more Java Records in hopes that the JVM does more with them
• Fixed some issue where plants could replace trees (i think there was a regression with placement somewhere)
• Fixed issue where the plugin didn't work with paper 1.21.5 craftbukkit mappings (trigged on beehives)
• Cave stalactites were accidentally disabled a year or so ago, readded them
• Added a config option for tree separation in plains