NPC refactor (#10122)

Co-authored-by: metalgearsloth <metalgearsloth@gmail.com>

Content.Client/NPC/ShowHTNCommand.cs

@@ -0,0 +1,16 @@
+using Content.Client.NPC.HTN;
+using Robust.Shared.Console;
+
+namespace Content.Client.NPC;
+
+public sealed class ShowHTNCommand : IConsoleCommand
+{
+    public string Command => "showhtn";
+    public string Description => "Shows the current status for HTN NPCs";
+    public string Help => $"{Command}";
+    public void Execute(IConsoleShell shell, string argStr, string[] args)
+    {
+        var npcs = IoCManager.Resolve<IEntitySystemManager>().GetEntitySystem<HTNSystem>();
+        npcs.EnableOverlay ^= true;
+    }
+}