Fix feature generation in the Deeper Down

[f-raZ0R]

• [x] Make most features not override big chunks of cities (no more lakes, woo!)
• [x] unfuck lizard den generation to make it stop overlapping with rock clusters in the razor edge
• [x] kill mojang with hammers why are deltas so cursed
• [ ] unfuck tall mushroom generation in noxwood forests
• [ ] AIR CHECK DISK IN NAME ONLY, FOR IT IS NEITHER
• [x] Understand mojank enough to somehow obtain the ability to make two features not overlap each other (if this can't be done in time i am fine considering this to be out of scope) eh this one's good enough besides the downstone in geodes im fine with this part
• [ ] fix my block predicate to use a different function, so it cares about the y value, as right now all features using this predicate will not be placed if there is a structure ANYWHERE in their chunk (THIS IS THE MOST IMPORTANT PART, I DO NOT CONSIDER THIS PR MERGE-READY UNTIL I DO THIS)