Changes, Fixes

• Probably fixes #74
• Some performance improvements
• If there is a problem with the material name in blocks.yml it'll log it in the console.
• General code cleanup and refactors.
• Changed blocks.yml worlds path, it's now:

worlds:
  world_nether:
    min-y: 0
    max-y: 128

Full Changelog: https://github.com/sarhatabaot/ChunkSpawnerLimiter/compare/v4.3.11...v4.3.12