Implement Nightmare Realm framework

[amot-dev]

• Phantom Soul Fragment
  • Add drop from Phantom with Sculk Sword
  • Add texture (based on Soul Fragment?)
• Dimensions
  • Add basic biome and dimension for 6 initial dimensions (for testing)
  • Serializer for seed-based dimension order and last exit location/dimension for each player
• Bed interactions
  • Right-click with Phantom Soul Fragment should add data component
  • Shift-right click with empty hand should remove data component
  • Right-click when there is data component should initialize transport via helper function

[amot-dev]

Also add gamerules to control sleeping while a player is in a Nightmare Realm:

• Disable
• Count them in total for sleeping players
• Do not count them in total for sleeping players