Add Multi-GPU Parallel Support to Connected Components CUDA Extension

[moqingyan]

Description:

This PR adds support for running the connected components CUDA extension on multiple GPUs in parallel.
Motivation:
Currently, the extension only supports single-GPU execution. Enabling multi-GPU allows for larger batch processing and improved performance in distributed training setups.

Changes:

Refactored kernel launch code to select devices dynamically.
Updated get_connected_componnets to accept a device argument and process batches in parallel across available GPUs.

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[hjj-lmx]

描述：

此 PR 增加了在多个 GPU 上并行运行 Connected Components CUDA 扩展的支持。 动机： 目前，该扩展仅支持单 GPU 执行。启用多 GPU 可以实现更大的批量处理，并提升分布式训练设置的性能。

变化：

重构了内核启动代码，使其能够动态选择设备。 更新了 get_connected_componnets，使其能够接受设备参数，并在可用的 GPU 上并行处理批次。

这是针对训练还是推理的多GPU