Refactor AI considerations (#1278)

Considerations are now instantiated under a manager and re-used between entities where they pass in their blackboard to get a score back.
Also makes the API a bit nicer to use.
Also some random cleanup.

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

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

@@ -0,0 +1,26 @@
+using System;
+using Content.Server.AI.WorldState;
+using Content.Server.AI.WorldState.States.Utility;
+
+namespace Content.Server.AI.Utility.Considerations.State
+{
+    /// <summary>
+    /// Simple NullCheck on a StoredState
+    /// </summary>
+    public sealed class StoredStateEntityIsNullCon : Consideration
+    {
+        public StoredStateEntityIsNullCon Set(Type type, Blackboard context)
+        {
+            // Ideally we'd just use a variable but then if we were iterating through multiple AI at once it'd be
+            // Stuffed so we need to store it on the AI's context.
+            context.GetState<StoredStateIsNullState>().SetValue(type);
+            return this;
+        }
+        
+        protected override float GetScore(Blackboard context)
+        {
+            var stateData = context.GetState<StoredStateIsNullState>().GetValue();
+            return stateData == null ? 1.0f : 0.0f;
+        }
+    }
+}

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

@@ -1,24 +0,0 @@
-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;
-        }
-    }
-}