Improve PD go runtime metrics

[bufferflies]

Enhancement Task

Background

Currently, PD's monitoring related to the Golang runtime lacks sufficient detail to effectively identify runtime-related issues. To address this, we need to enhance the existing Grafana monitoring panels and introduce additional monitoring metrics focused on the Golang runtime.

Objectives

The primary goal is to refine and expand the TiDB monitoring capabilities to provide more insightful data, which will aid in diagnosing runtime-related problems. The improvements will be implemented by optimizing the existing monitoring panels and adding new ones to cover critical runtime aspects.

details can be found in this: pingcap/tidb#55390

Task