[WIP][Core][GPU fraction][6/n] Migrate Node struct and callers from original class to base class pointer type

[dancingactor]

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[gemini-code-assist]

Code Review

This pull request introduces a polymorphic resource management architecture by establishing a NodeResourcesBase abstract class and a NodeResourcesV2 implementation. The V2 implementation enables per-instance resource tracking (specifically for GPU fractional scheduling) using NodeResourceInstanceSet. The Node structure and ClusterResourceManager have been refactored to manage these resources via unique pointers. The review feedback identifies several critical issues, including unsafe static_cast operations that will cause undefined behavior when V2 nodes are enabled, object slicing in GetNodeResources resulting in data loss, and malformed JSON generation in the DebugString method. There is also a recommendation to replace manual type checking with a virtual Clone pattern to improve the robustness of polymorphic copying.

[cursor]

Cursor Bugbot has reviewed your changes and found 2 potential issues.

^{Reviewed by Cursor Bugbot for commit c605a54. Configure here.}