(client) feat:实现掉落物，UI显示，维度

Client/Assets/Scripts/Data/EventDef.cs

@@ -0,0 +1,21 @@
+namespace Data
+{
+    public enum EventType
+    {
+        None,
+        SpawnCharacter,
+        SpawnBuilding,
+        SpawnBullet,
+        SpawnPickup,
+        SpawnDefaultEntity,
+    }
+    public class EventDef : Define
+    {
+        public EventType eventType = EventType.None;
+        public EntityDef entityDef_Character; // 用于 EventType.SpawnCharacter
+        public BuildingDef entityDef_Building;   // 用于 EventType.SpawnBuilding
+        public BulletDef entityDef_Bullet;     // 用于 EventType.SpawnBullet
+        public ItemDef entityDef_Pickup;       // 用于 EventType.SpawnPickup
+        public EventDef() { }
+    }
+}