move puzzle implementations out of engine

Assets/Engine/Runtime/Requirements/Placement/PlaceAnywhere.cs

@@ -0,0 +1,18 @@
+using System.Collections.Generic;
+using EscapeRoomEngine.Engine.Runtime.Modules;
+using UnityEngine;
+
+namespace EscapeRoomEngine.Engine.Runtime.Requirements.Placement
+{
+    /// <summary>
+    /// This requirement allows any placement. Used for testing purposes.
+    /// </summary>
+    [CreateAssetMenu(menuName = "Requirements/Place Anywhere")]
+    public class PlaceAnywhere : PlacementRequirement
+    {
+        protected override List<Utilities.Placement> FilterCandidates(List<Utilities.Placement> candidates, Module module, Space space)
+        {
+            return candidates;
+        }
+    }
+}