constants needed for some newish blocks, but not that many

[rkiddy]

$(mcmap) | grep 'Color of block' | awk '{print substr($0,47)}' | sort | uniq -c

-->

   2615 Color of block minecraft:bush not found
    698 Color of block minecraft:firefly_bush not found
    428 Color of block minecraft:iron_chain not found
  64273 Color of block minecraft:leaf_litter not found
   7726 Color of block minecraft:wildflowers not found

[rkiddy]

updated to fix a typo in the json. I can rebase and clean up the commits before I mark as not-draft.