feat: system service discovery should get ride of route-rule

[andrewshan]

What is the feature you want to add?
sdk discover polaris.discover, polaris.healthcheck, polaris.monitor, should not rely on route-rule

Why do you want to add this feature?
user install standalone version, he won't add the routerule to service

How to implement this feature?
use metadata routing instead of rulebase routing

Additional context
Add any other context or screenshots about the feature request here.

[wssgyyg]

polaris-cpp already user metadata routing to discover inner service.
https://github.com/polarismesh/polaris-cpp/blob/main/polaris/context.cpp#L374