feat(event): 添加订阅调整事件

- `编辑`订阅信息后，发送订阅调整事件
- 新增 `EventType.SubscribeModified` 枚举值
- 事件数据包含`subscribe_id: int` 和更新后的订阅信息`subscribe_info: dict`

app/schemas/types.py

@@ -48,6 +48,8 @@ class EventType(Enum):
     NoticeMessage = "notice.message"
     # 订阅已添加
     SubscribeAdded = "subscribe.added"
+    # 订阅已调整
+    SubscribeModified = "subscribe.modified"
     # 订阅已删除
     SubscribeDeleted = "subscribe.deleted"
     # 订阅已完成