Add utility AI (#806)

Co-authored-by: Pieter-Jan Briers <pieterjan.briers@gmail.com>
Co-authored-by: Metal Gear Sloth <metalgearsloth@gmail.com>
Co-authored-by: Pieter-Jan Briers <pieterjan.briers+git@gmail.com>

Content.Server/AI/WorldState/States/Nutrition/NearbyFoodState.cs

@@ -0,0 +1,43 @@
+using System.Collections.Generic;
+using Content.Server.AI.Utils;
+using Content.Server.GameObjects.Components;
+using Content.Server.GameObjects.Components.Movement;
+using Content.Server.GameObjects.Components.Nutrition;
+using JetBrains.Annotations;
+using Robust.Shared.Containers;
+using Robust.Shared.Interfaces.GameObjects;
+
+namespace Content.Server.AI.WorldState.States.Nutrition
+{
+    [UsedImplicitly]
+    public sealed class NearbyFoodState : CachedStateData<List<IEntity>>
+    {
+        public override string Name => "NearbyFood";
+
+        protected override List<IEntity> GetTrueValue()
+        {
+            var result = new List<IEntity>();
+
+            if (!Owner.TryGetComponent(out AiControllerComponent controller))
+            {
+                return result;
+            }
+
+            foreach (var entity in Visibility
+                .GetNearestEntities(Owner.Transform.GridPosition, typeof(FoodComponent), controller.VisionRadius))
+            {
+                if (ContainerHelpers.TryGetContainer(entity, out var container))
+                {
+                    if (!container.Owner.HasComponent<EntityStorageComponent>())
+                    {
+                        continue;
+                    }
+                }
+                result.Add(entity);
+            }
+
+            return result;
+
+        }
+    }
+}