feat(scene): add node serialization and batch restoration

[YuchenWell]

Background

Provide the cocos-cli foundation for cross-scene node copying by exporting selected node hierarchies as transferable data and restoring them in a target scene.

Changes

• Add Node.serialize and Node.createBySerializedData, serializing all selected roots together to preserve internal node and component references
• Reuse existing serialization and engine deserialization, with valueReplacer handling parent links, prefab metadata, and external references without modifying source nodes
• Support insertion position, world-transform preservation, and external-reference clearing or resolution
• Generate fresh identities for copies and preserve snapshot identities during Redo
• Record batch creation as one undo operation and roll back nodes and parent prefab metadata if mounting or snapshot capture fails

Scope

• Update Scene services, process proxies, and public type snapshots
• Add coverage for rollback, prefab handling, reference restoration, and Undo/Redo
• PinK clipboard and copy/paste UI integration will follow separately

Test Plan

• Serialize mutually referencing nodes in scene A, then restore them in scene B; internal references should point to the new nodes, while external references are cleared by default
• Restore a complete prefab instance and a separately copied child; the complete instance should retain its association, while the child should detach from the original instance
• Undo and redo batch creation; all roots and their internal references should be removed and restored together
• Inject mounting or snapshot failures; no nodes from the failed batch should remain in the target scene