Implement human pockets and ID card slot correctly.

Pockets & ID need uniform equipped. Pockets accept any sufficiently small item.

Content.Server/GameObjects/Components/GUI/HumanInventoryControllerComponent.cs

@@ -0,0 +1,87 @@
+using Robust.Server.GameObjects.Components.Container;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Interfaces.GameObjects;
+using Robust.Shared.Interfaces.Network;
+using Robust.Shared.Timers;
+using static Content.Shared.GameObjects.Components.Inventory.EquipmentSlotDefines;
+
+namespace Content.Server.GameObjects
+{
+    // Handles the special behavior of pockets/ID card slot and their relation to uniforms.
+    [RegisterComponent]
+    [ComponentReference(typeof(IInventoryController))]
+    public class HumanInventoryControllerComponent : Component, IInventoryController
+    {
+        public override string Name => "HumanInventoryController";
+
+        private InventoryComponent _inventory;
+
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            _inventory = Owner.GetComponent<InventoryComponent>();
+        }
+
+        bool IInventoryController.CanEquip(Slots slot, IEntity entity, bool flagsCheck)
+        {
+            var slotMask = SlotMasks[slot];
+
+            if ((slotMask & (SlotFlags.POCKET | SlotFlags.IDCARD)) != SlotFlags.NONE)
+            {
+                // Can't wear stuff in ID card or pockets unless you have a uniform.
+                if (_inventory.GetSlotItem(Slots.INNERCLOTHING) == null)
+                {
+                    return false;
+                }
+
+                if (slotMask == SlotFlags.POCKET)
+                {
+                    var itemComponent = entity.GetComponent<ItemComponent>();
+
+                    // If this item is small enough then it always fits in pockets.
+                    if (itemComponent.ObjectSize <= (int) ReferenceSizes.Pocket)
+                    {
+                        return true;
+                    }
+                }
+            }
+
+            // Standard flag check.
+            return flagsCheck;
+        }
+
+        public override void HandleMessage(ComponentMessage message, INetChannel netChannel = null, IComponent component = null)
+        {
+            base.HandleMessage(message, netChannel, component);
+
+            switch (message)
+            {
+                case ContainerContentsModifiedMessage contentsModified:
+                    Timer.Spawn(0, DropIdAndPocketsIfWeNoLongerHaveAUniform);
+                    break;
+            }
+        }
+
+        // Hey, it's descriptive.
+        private void DropIdAndPocketsIfWeNoLongerHaveAUniform()
+        {
+            if (_inventory.GetSlotItem(Slots.INNERCLOTHING) != null)
+            {
+                return;
+            }
+
+            void DropMaybe(Slots slot)
+            {
+                if (_inventory.GetSlotItem(slot) != null)
+                {
+                    _inventory.Unequip(slot);
+                }
+            }
+
+            DropMaybe(Slots.POCKET1);
+            DropMaybe(Slots.POCKET2);
+            DropMaybe(Slots.IDCARD);
+        }
+    }
+}