Pathfinder rework (#11452)

Content.Shared/NPC/Events/PathPolysRefreshMessage.cs

@@ -0,0 +1,15 @@
+using Robust.Shared.Serialization;
+
+namespace Content.Shared.NPC;
+
+[Serializable, NetSerializable]
+public sealed class PathPolysRefreshMessage : EntityEventArgs
+{
+    public EntityUid GridUid;
+    public Vector2i Origin;
+
+    /// <summary>
+    /// Multi-dimension arrays aren't supported so
+    /// </summary>
+    public Dictionary<Vector2i, List<DebugPathPoly>> Polys = new();
+}