OSPP Add some RPC metrics for Spring-Cloud-Admin

[kwings6]

Describe what this PR does / why we need it

为spring-cloud-admin项目进行埋点，提供指标。并且这些指标已经可以导出到Prometheus和Grafana中进行展示

Provide metrics for the Spring Cloud admin project. And these indicators can already be exported to Prometheus and Grafana for display

Does this pull request fix one issue?

NONE

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Describe how to verify it

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[kwings6]

通过Grafana可以展示RestTemplate的RPC请求的qps

Grafana can display the QPS of RestTemplate's RPC requests