Add PlayerOpenChestEvent

src/main/java/emu/grasscutter/server/event/player/PlayerOpenChestEvent.java

@@ -0,0 +1,33 @@
+package emu.grasscutter.server.event.player;
+
+import emu.grasscutter.game.entity.gadget.GadgetChest;
+import emu.grasscutter.game.player.Player;
+import emu.grasscutter.game.world.ChestReward;
+import emu.grasscutter.server.event.Cancellable;
+import emu.grasscutter.server.event.types.PlayerEvent;
+
+public final class PlayerOpenChestEvent extends PlayerEvent implements Cancellable {
+    private final GadgetChest chest;
+    private ChestReward reward;
+
+    public PlayerOpenChestEvent(Player player,
+                                GadgetChest chest, ChestReward reward
+    ) {
+        super(player);
+
+        this.chest = chest;
+        this.reward = reward;
+    }
+
+    public GadgetChest getChest() {
+        return this.chest;
+    }
+
+    public void setReward(ChestReward reward) {
+        this.reward = reward;
+    }
+
+    public ChestReward getReward() {
+        return this.reward;
+    }
+}