added the two interfaces for the FireSpreadStrategy and the FirefighterMovementStrategy

added the FireManager class

src/main/java/model/FireManager.java

+package model;
+
+import util.Position;
+
+import java.util.HashSet;
+import java.util.Set;
+
+public class FireManager {
+    private Set<Position> positions = new HashSet<>();
+    private FireSpreadStrategy fireSpread;
+}

src/main/java/model/FireSpreadStrategy.java

+package model;
+
+import util.Position;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+public interface FireSpreadStrategy {
+    List<Position> spreadFire(Set<Position> positions, Map<Position, List<Position>> neighbors);
+}

src/main/java/model/FirefighterMovementStrategy.java

+package model;
+
+import util.Position;
+import java.util.*;
+
+public interface FirefighterMovementStrategy {
+    Position moveToClosestFire(Position current, Set<Position> firePositions, Map<Position, List<Position>> neighbors);
+}