Levelup City Implementation (#2281)

* add statue promo data

* implement levelup city feature

* fix get level city when enter game

* format code

* fix typo, remove some property in the player, add the field cityInfoData to player class

src/main/java/emu/grasscutter/game/city/CityInfoData.java

@@ -0,0 +1,28 @@
+package emu.grasscutter.game.city;
+
+import dev.morphia.annotations.Entity;
+import emu.grasscutter.net.proto.CityInfoOuterClass.CityInfo;
+import lombok.Getter;
+import lombok.Setter;
+
+@Entity
+public class CityInfoData {
+    @Getter @Setter private int cityId;
+
+    @Getter @Setter
+    private int level = 1; // level of the city (include level SotS, level Frostbearing Trees, etc.)
+
+    @Getter @Setter private int numCrystal = 0; // number of crystals in the city
+
+    public CityInfoData(int cityId) {
+        this.cityId = cityId;
+    }
+
+    public CityInfo toProto() {
+        return CityInfo.newBuilder()
+                .setCityId(cityId)
+                .setLevel(level)
+                .setCrystalNum(numCrystal)
+                .build();
+    }
+}