NPC refactor (#10122)

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

Content.Server/NPC/HTN/HTNComponent.cs

@@ -0,0 +1,45 @@
+using System.Threading;
+using Content.Server.NPC.Components;
+using Robust.Shared.Serialization.TypeSerializers.Implementations.Custom.Prototype;
+
+namespace Content.Server.NPC.HTN;
+
+[RegisterComponent, ComponentReference(typeof(NPCComponent))]
+public sealed class HTNComponent : NPCComponent
+{
+    /// <summary>
+    /// The base task to use for planning
+    /// </summary>
+    [ViewVariables(VVAccess.ReadWrite),
+     DataField("rootTask", required: true, customTypeSerializer: typeof(PrototypeIdSerializer<HTNCompoundTask>))]
+    public string RootTask = default!;
+
+    /// <summary>
+    /// The NPC's current plan.
+    /// </summary>
+    [ViewVariables]
+    public HTNPlan? Plan;
+
+    /// <summary>
+    /// How long to wait after having planned to try planning again.
+    /// </summary>
+    [ViewVariables(VVAccess.ReadWrite), DataField("planCooldown")]
+    public float PlanCooldown = 0.45f;
+
+    /// <summary>
+    /// How much longer until we can try re-planning. This will happen even during update in case something changed.
+    /// </summary>
+    [ViewVariables(VVAccess.ReadWrite)]
+    public float PlanAccumulator = 0f;
+
+    [ViewVariables]
+    public HTNPlanJob? PlanningJob = null;
+
+    [ViewVariables]
+    public CancellationTokenSource? PlanningToken = null;
+
+    /// <summary>
+    /// Is this NPC currently planning?
+    /// </summary>
+    [ViewVariables] public bool Planning => PlanningJob != null;
+}