[Bug Report] VcImageryProviderTianditu - maximumLevel invalid

[FrozenJun]

VueCesium version

3.2.8

OS/Browsers version

windows 11 / chrome 118

Vue version

3.4.4

Cesium version

1.119.0

Reproduction Link

https://codepen.io/llisacxo-the-vuer/pen/qBzdNQN

Steps to reproduce

点击链接，摄像头移动至中国境内贴地，会出现白色色块

What is Expected?

摄像头很低时，最大的请求level一直是18

What is actually happening?

VcImageryProviderTianditu 设置 maximumLevel=18 ，摄像头很低时，请求level会出现 undefined和19/20。但高德的组件实测不会有这个问题

[zouyaoji]

设置成17哈