Add passthrough placement modifier, and add argument-less placed feature builder

src/main/kotlin/ru/dbotthepony/mc/otm/registry/MBuiltInRegistries.kt

@@ -56,7 +56,9 @@ object MBuiltInRegistries {
 	}
 
 	val FEATURE by Delegate(MRegistries.FEATURE)
-	val PLACEMENT_MODIFIER by Delegate(MRegistries.PLACEMENT_MODIFIER)
+	val PLACEMENT_MODIFIER by Delegate(MRegistries.PLACEMENT_MODIFIER) {
+		defaultKey(ResourceLocation(OverdriveThatMatters.MOD_ID, "passthrough"))
+	}
 
 	internal fun register(bus: IEventBus) {
 		delegates.forEach { bus.addListener(it::build) }

src/main/kotlin/ru/dbotthepony/mc/otm/worldgen/EnhancedPlacedFeature.kt

@@ -233,6 +233,8 @@ object EnhancedPlacedFeature : Feature<EnhancedPlacedFeature.Config>(
 		private val children = ArrayList<Builder>()
 		private val contents: Either<EnhancedPlacementModifier, Holder<EnhancedFeature.Configured<*, *>>>
 
+		constructor() : this(EnhancedPlacementModifier.Passthrough)
+
 		constructor(root: EnhancedPlacementModifier) {
 			this.root = null
 			this.contents = Either.left(root)

src/main/kotlin/ru/dbotthepony/mc/otm/worldgen/placement/EnhancedPlacementModifier.kt

@@ -39,11 +39,23 @@ interface EnhancedPlacementModifier {
 		}
 	}
 
+	object Passthrough : EnhancedPlacementModifier, Type<Passthrough> {
+		override fun evaluate(context: EnhancedPlacementContext, positions: Set<BlockPos>): Set<BlockPos> {
+			return positions
+		}
+
+		override val type: Type<*>
+			get() = this
+
+		override val codec: MapCodec<Passthrough> = MapCodec.unit(this)
+	}
+
 	companion object {
 		private val registrar = MDeferredRegister(MRegistries.PLACEMENT_MODIFIER)
 
 		init {
 			registrar.register("wrapper") { Wrapper.Companion }
+			registrar.register("passthrough") { Passthrough }
 		}
 
 		val CODEC: Codec<EnhancedPlacementModifier> by lazy {