[MC-184829] Village in custom superflat with no structures in the preset

From the changelog: "Flat level preset string lost structure settings ... we will restore some form of this functionality soon."

Expected results: No structures regardless of preset

Actual results: With the seed -3332015278762408732 and the below preset, you get a plains village in the wrong biome at (-4, 78, 92).

Preset:

minecraft:bedrock,5*minecraft:cyan_terracotta,5*minecraft:green_terracotta,5*minecraft:lime_terracotta,5*minecraft:yellow_terracotta,5*minecraft:orange_terracotta,5*minecraft:red_terracotta,5*minecraft:purple_terracotta,5*minecraft:blue_terracotta,5*minecraft:green_terracotta,5*minecraft:lime_terracotta,5*minecraft:yellow_terracotta,5*minecraft:orange_terracotta,5*minecraft:red_terracotta,5*minecraft:pink_terracotta,5*minecraft:white_terracotta;minecraft:badlands_plateau