Dynamic space world generation and debris. (#15120)

* World generation (squash)

* Test fixes.

* command

* o

* Access cleanup.

* Documentation touchups.

* Use a prototype serializer for BiomeSelectionComponent

* Struct enumerator in SimpleFloorPlanPopulatorSystem

* Safety margins around PoissonDiskSampler, cookie acquisition methodologies

* Struct enumerating PoissonDiskSampler; internal side

* Struct enumerating PoissonDiskSampler: Finish it

* Update WorldgenConfigSystem.cs

awa

---------

Co-authored-by: moonheart08 <moonheart08@users.noreply.github.com>
Co-authored-by: 20kdc <asdd2808@gmail.com>

Content.Server/Worldgen/Systems/LocalityLoaderSystem.cs

@@ -0,0 +1,59 @@
+using Content.Server.Worldgen.Components;
+using Robust.Server.GameObjects;
+
+namespace Content.Server.Worldgen.Systems;
+
+/// <summary>
+///     This handles loading in objects based on distance from player, using some metadata on chunks.
+/// </summary>
+public sealed class LocalityLoaderSystem : BaseWorldSystem
+{
+    [Dependency] private readonly TransformSystem _xformSys = default!;
+
+    /// <inheritdoc />
+    public override void Update(float frameTime)
+    {
+        var e = EntityQueryEnumerator<LocalityLoaderComponent, TransformComponent>();
+        var loadedQuery = GetEntityQuery<LoadedChunkComponent>();
+        var xformQuery = GetEntityQuery<TransformComponent>();
+        var controllerQuery = GetEntityQuery<WorldControllerComponent>();
+
+        while (e.MoveNext(out var uid, out var loadable, out var xform))
+        {
+            if (!controllerQuery.TryGetComponent(xform.MapUid, out var controller))
+                return;
+
+            var coords = GetChunkCoords(uid, xform);
+            var done = false;
+            for (var i = -1; i < 2 && !done; i++)
+            {
+                for (var j = -1; j < 2 && !done; j++)
+                {
+                    var chunk = GetOrCreateChunk(coords + (i, j), xform.MapUid!.Value, controller);
+                    if (!loadedQuery.TryGetComponent(chunk, out var loaded) || loaded.Loaders is null)
+                        continue;
+
+                    foreach (var loader in loaded.Loaders)
+                    {
+                        if (!xformQuery.TryGetComponent(loader, out var loaderXform))
+                            continue;
+
+                        if ((_xformSys.GetWorldPosition(loaderXform) - _xformSys.GetWorldPosition(xform)).Length > loadable.LoadingDistance)
+                            continue;
+
+                        RaiseLocalEvent(uid, new LocalStructureLoadedEvent());
+                        RemCompDeferred<LocalityLoaderComponent>(uid);
+                        done = true;
+                        break;
+                    }
+                }
+            }
+        }
+    }
+}
+
+/// <summary>
+///     A directed fired on a loadable entity when a local loader enters it's vicinity.
+/// </summary>
+public record struct LocalStructureLoadedEvent;
+