scheduler: improve the failed event of Reservation's scheduling

[ZiMengSheng]

Ⅰ. Describe what this PR does

The reservation plugin of koord-scheduler traverses all reservations with the Restricted policy and determines whether a certain Reservation satisfies the Pod. When all reservations cannot be satisfied, we lose reasonable information, such as which resources cannot be satisfied, which can help users diagnose themselves.

So this PR aggregate these messages to users.

Ⅱ. Does this pull request fix one issue?

fixes #1909

Ⅲ. Describe how to verify it

make pods requiring allocate resource from reservation, check the failed event, like follows.

Warning FailedScheduling 12s default-scheduler 0/50 nodes are available: 1 Insufficient cpu by reservation.

Ⅳ. Special notes for reviews

V. Checklist

• I have written necessary docs and comments
• I have added necessary unit tests and integration tests
• All checks passed in make test

[codecov]

Codecov Report

Attention: Patch coverage is 88.57143% with 4 lines in your changes are missing coverage. Please review.

Project coverage is 67.51%. Comparing base (3bf7ba8) to head (389e970).
Report is 3 commits behind head on main.

Files	Patch %	Lines
pkg/scheduler/plugins/reservation/plugin.go	88.57%	4 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1947   +/-   ##
=======================================
  Coverage   67.50%   67.51%           
=======================================
  Files         420      420           
  Lines       46961    47040   +79     
=======================================
+ Hits        31703    31760   +57     
- Misses      12949    12968   +19     
- Partials     2309     2312    +3     

Flag	Coverage Δ
unittests	67.51% <88.57%> (+<0.01%)	⬆️

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[eahydra]

/lgtm

[buptcozy]

/lgtm

[buptcozy]

/approve

[koordinator-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: buptcozy

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