scheduler: enhance ReservationNominator to support preemption

[eahydra]

Ⅰ. Describe what this PR does

The ReservationNominator interface and its implementation have been enhanced to support preemption scenarios.

When performing preemption at the job granularity level, many Pods will initiate preemption in the PostFilter stage. As each Pod secures resources, the ReservationNominator.NominateReservation method is called to elect a Reservation. The ReservationNominator.AddNominatedReservation and PreFilterExtension.AddPod methods are then used to record the Request quantity. This ensures that the preemption results of one Pod can be perceived by the next Pod during its preemption process.

When a new scheduling cycle begins, there is a possibility that a Pod awaiting scheduling may trigger the PreFilterExtension.AddPod again. Since the AddNominatedReservation method has already recorded that the Pod has reserved resources on a certain node, it ensures that this reserved resource will not be taken by lower-priority Pods.

Ⅱ. Does this pull request fix one issue?

Ⅲ. Describe how to verify it

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

[eahydra]

/hold need more testing

[codecov]

Codecov Report

Attention: 33 lines in your changes are missing coverage. Please review.

Comparison is base (82e71dc) 66.48% compared to head (95a8b5e) 66.50%.
Report is 1 commits behind head on main.

Files	Patch %	Lines
pkg/scheduler/frameworkext/framework_extender.go	6.66%	13 Missing and 1 partial ⚠️
.../frameworkext/eventhandlers/reservation_handler.go	10.00%	8 Missing and 1 partial ⚠️
pkg/scheduler/plugins/reservation/nominator.go	87.50%	4 Missing and 1 partial ⚠️
...heduler/frameworkext/framework_extender_factory.go	20.00%	4 Missing ⚠️
pkg/scheduler/plugins/reservation/plugin.go	92.30%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1804      +/-   ##
==========================================
+ Coverage   66.48%   66.50%   +0.02%     
==========================================
  Files         396      395       -1     
  Lines       43754    43820      +66     
==========================================
+ Hits        29088    29144      +56     
- Misses      12510    12516       +6     
- Partials     2156     2160       +4     

Flag	Coverage Δ
unittests	66.50% <69.44%> (+0.02%)	⬆️

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[eahydra]

/hold cancel

[buptcozy]

/lgtm

[koordinator-bot]

[APPROVALNOTIFIER] This PR is APPROVED

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