Add utility AI (#806)

Co-authored-by: Pieter-Jan Briers <pieterjan.briers@gmail.com>
Co-authored-by: Metal Gear Sloth <metalgearsloth@gmail.com>
Co-authored-by: Pieter-Jan Briers <pieterjan.briers+git@gmail.com>

Content.Server/AI/Utility/Considerations/State/StoredStateIsNullCon.cs

@@ -0,0 +1,24 @@
+using Content.Server.AI.Utility.Curves;
+using Content.Server.AI.WorldState;
+
+namespace Content.Server.AI.Utility.Considerations.State
+{
+    /// <summary>
+    /// Simple NullCheck on a StoredState
+    /// </summary>
+    public sealed class StoredStateIsNullCon<T, U> : Consideration where T : StoredStateData<U>
+    {
+        public StoredStateIsNullCon(IResponseCurve curve) : base(curve) {}
+
+        public override float GetScore(Blackboard context)
+        {
+            var state = context.GetState<T>();
+            if (state.GetValue() == null)
+            {
+                return 1.0f;
+            }
+
+            return 0.0f;
+        }
+    }
+}