支持多个k8s集群service发现

[lemon65535]

Why do you need it?

Is your feature request related to a problem? Please describe in details
我们这边内部不止一个k8s集群，如果在每个k8s集群中都安装一个higress的话，后续管理维护比较困难，而且还要在higress上层再做一层反向代理的调度。
所以我们希望higress能够支持对接多个k8s集群的service实现服务发现

How could it be?

A clear and concise description of what you want to happen. You can explain more about input of the feature, and output of it.
能够支持接入k8s类型的服务来源

并且针对多个k8s集群的相同的namespace，相同的service名称，能支持聚合后端endpoint
针对不同的k8s集群，最好能支持配置不同的权重支持

Other related information

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