feat: add some metrics about RT

[ev1lQuark]

The minimum response time (min rt) metrics for different labels are maintained using sync.Map. The purpose of labels is to differentiate between different provider-consumer RPC invocation paths. For example, if provider A offers a service and is called by two consumers, Consumer A and Consumer B, the minimum response time for each path needs to be tracked separately.

Please provide suggestions for the code organization, naming, and implementation approach for this PR.

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使用sync.Map对于不同 label 的最小响应时间（min rt）指标进行维护。label 的作用是区分不同的 provider-consumer RPC 调用链路，比如 provider A 提供的服务被 consumer A 和 Consumer B 两个消费者去调用，则两条链路的最小响应时间需要分别统计。

请对于本 PR 代码组织方式、命名、实现思路提出建议。

[jasondeng1997]

pls fix the ci

[codecov-commenter]

Codecov Report

Merging #2340 (524b32b) into main (95b463b) will increase coverage by 0.13%.
The diff coverage is 76.19%.

❗ Current head 524b32b differs from pull request most recent head 38373b5. Consider uploading reports for the commit 38373b5 to get more accurate results

@@            Coverage Diff             @@
##             main    #2340      +/-   ##
==========================================
+ Coverage   44.10%   44.23%   +0.13%     
==========================================
  Files         294      294              
  Lines       17890    18018     +128     
==========================================
+ Hits         7890     7971      +81     
- Misses       9161     9201      +40     
- Partials      839      846       +7     

Impacted Files	Coverage Δ
filter/metrics/filter.go	73.91% <0.00%> (-11.09%)	⬇️
metrics/prometheus/model.go	33.54% <62.12%> (ø)
metrics/prometheus/reporter.go	75.55% <80.32%> (+22.22%)	⬆️
metrics/prometheus/metric_set.go	100.00% <100.00%> (ø)
metrics/prometheus/util.go	100.00% <100.00%> (ø)

... and 1 file with indirect coverage changes

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[ev1lQuark]

1. Add more metrics:
   • dubbo_xxx_rt_milliseconds_max
   • dubbo_xxx_rt_milliseconds_avg
   • dubbo_xxx_rt_milliseconds_sum
   • dubbo_xxx_rt_milliseconds_last
2. refactor some file names and method names

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
0.0% Duplication

[chickenlj]

LGTM.

[justxuewei]

Lgtm, thanks!