Add rolling window QPS tracker

[Shaddoll]

What changed?
Add rolling window QPS tracker

Why?
Rolling window QPS tracker is more responsive and accurate but doesn't smooth fluctuations. We will compare it with EMAFixedWindowQPS tracker to see which is more suitable for our use case.

How did you test it?
unit tests

Potential risks

Release notes

Documentation Changes

[codecov]

Codecov Report

Attention: Patch coverage is 90.90909% with 3 lines in your changes missing coverage. Please review.

Project coverage is 73.20%. Comparing base (dc51527) to head (a532b47).
Report is 5 commits behind head on master.

Files with missing lines	Patch %	Lines
common/stats/stats.go	90.90%	2 Missing and 1 partial ⚠️

Additional details and impacted files

Files with missing lines	Coverage Δ
common/stats/stats.go	90.90% <90.90%> (ø)

... and 4 files with indirect coverage changes

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