WIP: Add disconnect notification feature to Web

[Senorsen]

! This commit should be rebased once https://github.com/GyrosWorkshop/WukongClient/pull/1 is released.

For detailed information:

• https://github.com/GyrosWorkshop/Wukong/blob/master/Wukong/Services/Socket.cs
• https://github.com/GyrosWorkshop/WukongAndroid/blob/master/wukong/src/main/java/com/senorsen/wukong/network/SocketClient.kt
• https://github.com/GyrosWorkshop/WukongClient/pull/1

[Senorsen]

因为依赖还未部署，所以 CI 一定会 fail 。

部署依赖后会进行 rebase commit 。