feat: add InterpretSchedulingResult operation to ResourceInterpreter

[ljluestc]

This PR implements the feature requested in GitHub issue #3459 to enable interpreting customized scheduling results in the ResourceInterpreter.

The issue describes two critical scenarios that need to be addressed:

1. Remainder Distribution Problem: When distributing replicas across clusters with equal weights, remainders from uneven division always go to the same cluster. For workloads with replicas = 1 or when replica counts can't be evenly divided by cluster weights, Karmada currently schedules remainders to the same cluster consistently, leading to imbalanced resource utilization.

2. Member Cluster Synchronization: When HPA controllers work independently in member clusters, replica changes need to be synchronized back to the control plane to maintain a consistent global perspective and prevent workload disruption during cluster transitions.

This PR adds a new InterpretSchedulingResult operation to the ResourceInterpreter framework that allows customizing how replicas are distributed among clusters through:

• Declarative Lua scripts for custom scheduling logic
• Webhook-based customization for external scheduling services
• Third-party resource support for extended scheduling capabilities
• Full backward compatibility with existing behavior

Which issue(s) this PR fixes

Fixes #3459

Special notes for your reviewer

This implementation provides a flexible framework for custom scheduling algorithms while maintaining full backward compatibility. The feature is opt-in and only activates when explicitly configured.

Key architectural decisions:

• Added new InterpreterOperationInterpretSchedulingResult operation type
• Extended ResourceInterpreter interface with InterpretSchedulingResult() method
• Implemented in all interpreter types (Default, Declarative, Webhook, Third-party)
• Added comprehensive test coverage including unit and integration tests

Does this PR introduce a user-facing change?

`ResourceInterpreter`: Added new `InterpretSchedulingResult` operation to enable customizing replica distribution across clusters. This allows:

1. Custom scheduling logic for distributing remainders across clusters instead of always assigning them to the same cluster
2. Synchronization of replica changes from member clusters back to control plane when HPA controllers work independently

Users can now configure custom scheduling behavior through:
- Lua scripts in ResourceInterpreterCustomization
- Webhook services for external scheduling logic
- Third-party resource interpreters

The feature is backward compatible and only activates when explicitly configured.

---

Detailed Implementation

API Extensions

• Added InterpreterOperationInterpretSchedulingResult operation type to configv1alpha1
• Extended ResourceInterpreter interface with InterpretSchedulingResult(object, schedulingResult) ([]TargetCluster, error) method
• Added SchedulingResultInterpretation type for declarative configurations
• Extended webhook request/response attributes to include scheduling results

Interpreter Implementations

• Default Interpreter: Returns scheduling result unchanged (maintains backward compatibility)
• Declarative Interpreter: Supports Lua scripts for custom scheduling logic
• Webhook Interpreter: Enables external services to customize scheduling results
• Third-party Interpreter: Supports third-party resource scheduling customization

Lua VM Integration

• Added InterpretSchedulingResult() method to Lua VM for script execution
• Implemented ConvertLuaResultToTargetClusters() for Lua-to-Go conversion
• Full Lua script support for complex scheduling algorithms

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[XiShanYongYe-Chang]

Hi @ljluestc, thank you for participating in Karmada.

I would like to know, apart from the issue you mentioned, what is your user scenario?