Split ConfigurationService to use SimulationService

Methods concerning engine make use of EngineService, those concerning grid and patterns make use of SimulationService.

lib/service/simulation_service.dart

@@ -1,19 +1,27 @@
+import 'dart:math';
+
 import 'package:rules_of_living/service/engine_service.dart';
 
 class SimulationService {
-  final EngineService engine;
+  final EngineService _engine;
 
-  SimulationService(this.engine);
+  SimulationService(this._engine);
 
   void reset() {
-    engine.reset();
+    _engine.reset();
   }
 
   void addRandomPattern() {
-    engine.addRandomPattern();
+    _engine.addRandomPattern();
   }
 
   void clear() {
-    engine.clear();
+    _engine.clear();
   }
+
+  void set gridSize(Point size) {
+    _engine.engine.gridSize = size;
+  }
+
+  Point<int> get gridSize => _engine.engine.gridSize;
 }