This pull request renames buckets so that they use the `mcl_` naming convention.
I originally was going to do some renaming on a bigger scope, but decided against it for now.
Reviewed-on: MineClone2/MineClone2#3708
Reviewed-by: ancientmarinerdev <ancientmariner_dev@proton.me>
Co-authored-by: FossFanatic <fossfanatic@noreply.git.minetest.land>
Co-committed-by: FossFanatic <fossfanatic@noreply.git.minetest.land>