proposal: introducing a scheduling strategy to customize cluster propagation priorities

[chaosi-zju]

What type of PR is this?

/kind feature
/kind design

What this PR does / why we need it:

This proposal introduces a new user scenario for scheduling, where users have preferences for clusters with
varying priorities and want replicas assigned to their preferred clusters.

To support this scenario, we propose two alternative solutions: one is adding aggregatePreference to the existing
Weighted replica scheduling strategy, and the other is enhancing the capability of multiple scheduling groups.

Ultimately, we compare these two options and decide on the best implementation to provide a scheduling strategy
that allows users to customize cluster propagation priorities.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

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Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 42.42%. Comparing base (32c2ef7) to head (6921114).
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Additional details and impacted files

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+ Coverage   31.70%   42.42%   +10.71%     
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  Files         643      656       +13     
  Lines       44445    55884    +11439     
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+ Hits        14090    23707     +9617     
- Misses      29325    30658     +1333     
- Partials     1030     1519      +489     

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unittests	42.42% <ø> (+10.71%)	⬆️

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[zhzhuang-zju]

Could explicit priority declaration for clusters be implemented, considering the following points:

• We can define the priority of clusters as an inherent attribute of the clusters themselves. Various scheduling methods would then act merely as consumers of this data, avoiding binding them directly to any specific scheduling approach.
• The current Solution 2 has coupling between different clusterAffinities, which requires determining the priority of clusters based on the order in which clusters appear within the clusterAffinity. Additionally, it does not allow for distinguishing the priority relationship between clusters that appear for the first time within the same clusterAffinity.

[chaosi-zju]

/retest