Stacked sprite visualizer (#3096)

* Add Stack Visualizer

* Add cigarette pack resources

Adds transparent layers for visualizing cigarettes

* Add Bag Open/Close Visualizer

So storage opened in inventory can have different icons when opened
or closed.

* Create a component that only enumerates single item

Used for creating stuff like matchbox, or cigarettes. As a bonus.
It will only update stack visualizer for that particullar item.

* Refactoring stuff

* Fix other usage of stack in Resources

* Add docs

* Apply suggestions from code review

Apply metalgearsloth suggestions

Co-authored-by: metalgearsloth <31366439+metalgearsloth@users.noreply.github.com>

* Applied suggestions from metalgearsloth

* Changed SingleItemStorageComponent to StorageCounterComponent

Difference. New component doesn't spawn items, merely counts them.

* Refactored StackVisualizer

* Fix breakage with master

* Update Resources/Prototypes/Entities/Objects/Consumable/fancy.yml

Co-authored-by: metalgearsloth <31366439+metalgearsloth@users.noreply.github.com>

* Update with MGS suggestions

Co-authored-by: metalgearsloth <31366439+metalgearsloth@users.noreply.github.com>

Content.Server/GameObjects/Components/Items/Storage/StorageCounterComponent.cs

@@ -0,0 +1,86 @@
+#nullable enable
+
+using System.Collections.Generic;
+using Content.Shared.GameObjects.Components;
+using Content.Shared.GameObjects.Components.Tag;
+using Robust.Server.GameObjects;
+using Robust.Shared.GameObjects;
+using Robust.Shared.Log;
+using Robust.Shared.Serialization;
+
+namespace Content.Server.GameObjects.Components.Items.Storage
+{
+    /// <summary>
+    /// Storage that spawns and counts a single item.
+    /// Usually used for things like matchboxes, cigarette packs,
+    /// cigar cases etc.
+    /// </summary>
+    /// <code>
+    ///  - type: StorageCounter
+    ///    amount: 6 # Note: this field can be omitted
+    ///    countTag: Cigarette # Note: field doesn't point to entity Id, but its tag
+    /// </code>
+    [RegisterComponent]
+    public class StorageCounterComponent : Component
+    {
+        private string? _countTag;
+        private int? _maxAmount;
+
+        /// <summary>
+        /// Single item storage component usually have an attached StackedVisualizer.
+        /// </summary>
+        [ComponentDependency] private readonly AppearanceComponent? _appearanceComponent = default;
+
+        public override string Name => "StorageCounter";
+
+        public override void ExposeData(ObjectSerializer serializer)
+        {
+            base.ExposeData(serializer);
+
+            serializer.DataField(ref _countTag, "countTag", null);
+            if (_countTag == null)
+            {
+                Logger.Warning("StorageCounterComponent without a `countTag` is useless");
+            }
+            serializer.DataField(ref _maxAmount, "amount", null);
+        }
+
+        public override void HandleMessage(ComponentMessage message, IComponent? component)
+        {
+            base.HandleMessage(message, component);
+
+            if (_appearanceComponent != null)
+            {
+                switch (message)
+                {
+                    case ContainerContentsModifiedMessage msg:
+                        var actual = Count(msg.Container.ContainedEntities);
+                        _appearanceComponent.SetData(StackVisuals.Actual, actual);
+                        if (_maxAmount != null)
+                        {
+                            _appearanceComponent.SetData(StackVisuals.MaxCount, _maxAmount);
+                        }
+
+                        break;
+                }
+            }
+        }
+
+        private int Count(IReadOnlyList<IEntity> containerContainedEntities)
+        {
+            var count = 0;
+            if (_countTag != null)
+            {
+                foreach (var entity in containerContainedEntities)
+                {
+                    if (entity.HasTag(_countTag))
+                    {
+                        count++;
+                    }
+                }
+            }
+
+            return count;
+        }
+    }
+}