NPC refactor (#10122)

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

Content.Server/NPC/Commands/AddNPCCommand.cs

@@ -0,0 +1,46 @@
+using Content.Server.Administration;
+using Content.Server.NPC.HTN;
+using Content.Shared.Administration;
+using Robust.Shared.Console;
+
+namespace Content.Server.NPC.Commands
+{
+    [AdminCommand(AdminFlags.Fun)]
+    public sealed class AddNPCCommand : IConsoleCommand
+    {
+        [Dependency] private readonly IEntityManager _entities = default!;
+
+        public string Command => "addnpc";
+        public string Description => "Add a HTN NPC component with a given root task";
+        public string Help => "Usage: addnpc <entityId> <rootTask>"
+                              + "\n    entityID: Uid of entity to add the AiControllerComponent to. Open its VV menu to find this."
+                              + "\n    rootTask: Name of a behaviorset to add to the component on initialize.";
+
+        public void Execute(IConsoleShell shell, string argStr, string[] args)
+        {
+            if (args.Length != 2)
+            {
+                shell.WriteError("Wrong number of args.");
+                return;
+            }
+
+            var entId = new EntityUid(int.Parse(args[0]));
+
+            if (!_entities.EntityExists(entId))
+            {
+                shell.WriteError($"Unable to find entity with uid {entId}");
+                return;
+            }
+
+            if (_entities.HasComponent<HTNComponent>(entId))
+            {
+                shell.WriteError("Entity already has an NPC component.");
+                return;
+            }
+
+            var comp = _entities.AddComponent<HTNComponent>(entId);
+            comp.RootTask = args[1];
+            shell.WriteLine("AI component added.");
+        }
+    }
+}