Confusing naming in VegetationPlacedFeatures

[Juuxel]

• modifiers(int) uses WORLD_SURFACE_WG_HEIGHTMAP and is used for general vegetation (grass, ferns, flowers etc)
• modifiersWithChance(int, PlacementModifier) uses MOTION_BLOCKING_HEIGHTMAP and is used for mushrooms
  • Suggested rename: mushroomModifiers
• modifiersBuilder(PlacementModifier), modifiers(PlacementModifier) and modifiersWithWouldSurvice(PlacementModifier, Block) use OCEAN_FLOOR_HEIGHTMAP and are used for trees
  • Suggested renames: treeModifiersBuilder, treeModifiers, treeModifiersWithWouldSurvive

This distinction should be reflected in the names as the behaviour is different.