koordlet: support collect BE CPU metric

[jasonliu747]

Signed-off-by: Jason Liu jasonliu747@gmail.com

Ⅰ. Describe what this PR does

This PR will make metricadvisor be able to collect BE CPU metric.

Ⅱ. Does this pull request fix one issue?

Ⅲ. Describe how to verify it

Ⅳ. Special notes for reviews

[codecov-commenter]

Codecov Report

Merging #158 (f2ae38c) into main (3e70943) will increase coverage by 0.10%.
The diff coverage is 60.71%.

❗ Current head f2ae38c differs from pull request most recent head a7356d6. Consider uploading reports for the commit a7356d6 to get more accurate results

@@            Coverage Diff             @@
##             main     #158      +/-   ##
==========================================
+ Coverage   57.72%   57.82%   +0.10%     
==========================================
  Files          90       91       +1     
  Lines        8056     8159     +103     
==========================================
+ Hits         4650     4718      +68     
- Misses       3002     3029      +27     
- Partials      404      412       +8     

Flag	Coverage Δ
unittests	57.82% <60.71%> (+0.10%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
pkg/koordlet/metricsadvisor/collector.go	9.69% <0.00%> (-0.03%)	⬇️
pkg/util/container.go	30.62% <0.00%> (+1.28%)	⬆️
pkg/util/node.go	29.62% <0.00%> (-23.71%)	⬇️
pkg/koordlet/metricsadvisor/be_collector.go	68.81% <68.81%> (ø)
pkg/util/stat.go	82.14% <100.00%> (+1.37%)	⬆️

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[saintube]

/lgtm

[hormes]

/lgtm
/approve

[koordinator-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: hormes

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