VGRoid support (#27659)

* Dungeon spawn support for grid spawns

* Recursive dungeons working

* Mask approach working

* zack

* More work

* Fix recursive dungeons

* Heap of work

* weh

* the cud

* rar

* Job

* weh

* weh

* weh

* Master merges

* orch

* weh

* vgroid most of the work

* Tweaks

* Tweaks

* weh

* do do do do do do

* Basic layout

* Ore spawning working

* Big breaking changes

* Mob gen working

* weh

* Finalising

* emo

* More finalising

* reverty

* Reduce distance

Content.Shared/Procedural/DungeonGenerators/ReplaceTileDunGen.cs

@@ -0,0 +1,30 @@
+using Content.Shared.Maps;
+using Robust.Shared.Noise;
+using Robust.Shared.Prototypes;
+
+namespace Content.Shared.Procedural.DungeonGenerators;
+
+/// <summary>
+/// Replaces existing tiles if they're not empty.
+/// </summary>
+public sealed partial class ReplaceTileDunGen : IDunGenLayer
+{
+    /// <summary>
+    /// Chance for a non-variant tile to be used, in case they're too noisy.
+    /// </summary>
+    [DataField]
+    public float VariantWeight = 0.1f;
+
+    [DataField(required: true)]
+    public List<ReplaceTileLayer> Layers = new();
+}
+
+[DataRecord]
+public record struct ReplaceTileLayer
+{
+    public ProtoId<ContentTileDefinition> Tile;
+
+    public float Threshold;
+
+    public FastNoiseLite Noise;
+}