Add a debug overlay for accessreaders (#9681)

> didnt pjb have issues with doing the control stuff in an overlay and just wanted direct texture draw

I ended up doing dis.

Content.Client/Access/AccessOverlay.cs

@@ -0,0 +1,79 @@
+using System.Text;
+using Content.Client.Resources;
+using Content.Shared.Access.Components;
+using Robust.Client.Graphics;
+using Robust.Client.ResourceManagement;
+using Robust.Shared.Enums;
+
+namespace Content.Client.Access;
+
+public sealed class AccessOverlay : Overlay
+{
+    private readonly IEntityManager _entityManager;
+    private readonly EntityLookupSystem _lookup;
+    private readonly Font _font;
+
+    public override OverlaySpace Space => OverlaySpace.ScreenSpace;
+
+    public AccessOverlay(IEntityManager entManager, IResourceCache cache, EntityLookupSystem lookup)
+    {
+        _entityManager = entManager;
+        _lookup = lookup;
+
+        _font = cache.GetFont("/Fonts/NotoSans/NotoSans-Regular.ttf", 12);
+    }
+
+    protected override void Draw(in OverlayDrawArgs args)
+    {
+        if (args.ViewportControl == null)
+            return;
+
+        var readerQuery = _entityManager.GetEntityQuery<AccessReaderComponent>();
+        var xformQuery = _entityManager.GetEntityQuery<TransformComponent>();
+
+        foreach (var ent in _lookup.GetEntitiesIntersecting(args.MapId, args.WorldAABB,
+                         LookupFlags.Anchored | LookupFlags.Approximate))
+        {
+            if (!readerQuery.TryGetComponent(ent, out var reader) ||
+                !xformQuery.TryGetComponent(ent, out var xform))
+            {
+                continue;
+            }
+
+            var text = new StringBuilder();
+            var index = 0;
+            var a = $"{_entityManager.ToPrettyString(ent)}";
+            text.Append(a);
+
+            foreach (var list in reader.AccessLists)
+            {
+                a = $"Tag {index}";
+                text.AppendLine(a);
+
+                foreach (var entry in list)
+                {
+                    a = $"- {entry}";
+                    text.AppendLine(a);
+                }
+
+                index++;
+            }
+
+            string textStr;
+
+            if (text.Length >= 2)
+            {
+                textStr = text.ToString();
+                textStr = textStr[..^2];
+            }
+            else
+            {
+                textStr = "";
+            }
+
+            var screenPos = args.ViewportControl.WorldToScreen(xform.WorldPosition);
+
+            args.ScreenHandle.DrawString(_font, screenPos, textStr, Color.Gold);
+        }
+    }
+}