Migrate ABMs to nodetimers and LBMs

[Montandalar]

Base Minetest Game registers approximately 12 ABMs. Just MTG and Australia mod currently has 37, and it only gets worse with the whole Aussieforks modpack.

• [x] All coral growth ABMs should be moved to nodetimers, or if that's not possible, one ABM or as few as possible.
• [x] Woodship and submarine ABMs should be moved to LBMs or eliminated through the use of a callback like on_construct if possible.
• [x] The intent of the ABMs in noairblocks.lua need to be reverse-engineered and the code improved. I think at least a small improvement is possible, but possibly a large one. Is the first ABM even necessary?

[Montandalar]

The intent of the ABMs in noairblocks is to cause the death (e.g. coral bleaching) of nodes exposed to the air. This will be replaced with nodetimers on living kelps and corals and the file will probably be removed entirely.