`aem` better aemaacs instanceId lookup

When aem is registering as an Adobe I/O Event provider
we need to uniquely identify skyline author clusters at runtime

we‘ve been using the `author` externalizer service to compute the root url.
as it is matching the skyline author's environment public url

We believe we could do a better more user friendly job here to name this and label this environment.
May be relying on pre-populated Cloud Manager environment variables ....

未识别出文件或测试。首先跟踪将 aem 注册为 Adobe I/O Event provider 的过程，以及当前用于计算 root URL 的 author externalizer service；明确所需的 instanceId 和 environment-label 行为。当 Skyline author clusters 能够在运行时被唯一识别，并具有用户友好的环境名称时，工作即告完成。

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