Simulate the generation of Ocean Ruins
Notice: Every room is initially generated as brick, then replaced by cracked, and then mossy variation
Thus our generateLoot will return 3 chests for one single room, ususally the last one accords with in-game chest, for other cases you should check mannually.
(the generator is verified in 1.16.1, I guess also valid for 1.13.2--1.17.1)
Thanks for help: Xinyuuu7, Neil
If you want to run this you also need seedfinding libraries