Unnamed Desert

<Minor Update>

• Structures
  • 'Fossil'
    • Added structure 'Triceratops Skull Fossil' (1 variant)
    • Added structure 'Tyrannosaurus Skull Fossil' (1 variant)
• Miscellaneous
  • Fixed 'Pillager Outpost' processor list
  • Fixed 'Fossil' processor list
  • Improved terrain integration
    • Adapted project_start_to_heightmap for some structures
    • Expanded internal block replacement
  • Internal restructuring
    • Reclassified 'Cactus' structure as desert structure
    • Reclassified 'Skeleton' structure as badlands structure
    • Reclassified 'Termite Mound' structure as badlands structure
    • Restructured structure sets