feat(koordlet): support memoryEvictLowerPercent in memory evict

[shinytang6]

Ⅰ. Describe what this PR does

Ⅱ. Does this pull request fix one issue?

resolves #85

Ⅲ. Describe how to verify it

Ⅳ. Special notes for reviews

[codecov-commenter]

Codecov Report

Merging #132 (74c8cde) into main (6200cdc) will increase coverage by 0.91%.
The diff coverage is 75.00%.

@@            Coverage Diff             @@
##             main     #132      +/-   ##
==========================================
+ Coverage   56.38%   57.29%   +0.91%     
==========================================
  Files          78       78              
  Lines        7366     7376      +10     
==========================================
+ Hits         4153     4226      +73     
+ Misses       2840     2767      -73     
- Partials      373      383      +10     

Flag	Coverage Δ
unittests	57.29% <75.00%> (+0.91%)	⬆️

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

Impacted Files	Coverage Δ
pkg/koordlet/resmanager/memory_evict.go	72.07% <75.00%> (+59.20%)	⬆️
pkg/koordlet/resmanager/resmanager.go	56.69% <0.00%> (+2.67%)	⬆️

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[jasonliu747]

nice, one tiny suggestion.

[jasonliu747]

/lgtm

[hormes]

/approve

[koordinator-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: hormes, jasonliu747

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