Revert biome rework (#38724)

* Revert "Fix world generation (#38713)"

This reverts commit 10fa6ff4af.

* Revert "Biome rework (#37735)"

This reverts commit fe7b96147c.

Content.Shared/Procedural/PostGeneration/BoundaryWallDunGen.cs

@@ -0,0 +1,35 @@
+using Content.Shared.Maps;
+using Robust.Shared.Prototypes;
+
+namespace Content.Shared.Procedural.PostGeneration;
+
+/// <summary>
+/// Iterates room edges and places the relevant tiles and walls on any free indices.
+/// </summary>
+/// <remarks>
+/// Dungeon data keys are:
+/// - CornerWalls (Optional)
+/// - FallbackTile
+/// - Walls
+/// </remarks>
+public sealed partial class BoundaryWallDunGen : IDunGenLayer
+{
+    [DataField]
+    public BoundaryWallFlags Flags = BoundaryWallFlags.Corridors | BoundaryWallFlags.Rooms;
+
+    [DataField(required: true)]
+    public EntProtoId Wall;
+
+    [DataField]
+    public EntProtoId? CornerWall;
+
+    [DataField(required: true)]
+    public ProtoId<ContentTileDefinition> Tile;
+}
+
+[Flags]
+public enum BoundaryWallFlags : byte
+{
+    Rooms = 1 << 0,
+    Corridors = 1 << 1,
+}