move puzzle implementations out of engine

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

@@ -0,0 +1,35 @@
+using System.Collections.Generic;
+using EscapeRoomEngine.Engine.Runtime.Modules;
+using UnityEngine;
+
+namespace EscapeRoomEngine.Engine.Runtime.Requirements.Placement
+{
+    /// <summary>
+    /// This requirement prevents modules from overlapping. For two models not to overlap, both of them need this requirement.
+    /// </summary>
+    [CreateAssetMenu(menuName = "Requirements/No Overlap")]
+    public class NoOverlap : PlacementRequirement
+    {
+        protected override List<Utilities.Placement> FilterCandidates(List<Utilities.Placement> candidates, Module module, Space space)
+        {
+            space.AllModules.ForEach(other => // for all other module ...
+                other.srPlacement.ForEachPosition(otherPosition => // ... positions ...
+                    candidates.RemoveAll(candidate => // ... remove every candidate that ...
+                    {
+                        var remove = false;
+                        
+                        candidate.ForEachPosition(position => // ... anywhere inside its bounds ...
+                        {
+                            if (!remove)
+                            {
+                                remove = position.Equals(otherPosition); // ... overlaps with other modules' position
+                            }
+                        });
+                        
+                        return remove;
+                    })));
+
+            return candidates;
+        }
+    }
+}