OPENABC_DATASET (OPENABC-D) with Latest PyG 2.x Support

Convert and repackage the original OPENABC dataset (OPENABC-D) to a format supported by PyG (PyTorch Geometric) 2.x, while preserving the same data structure and interfaces as the original dataset. --- This archive was created using split (multi-volume) ZIP compression. To extract it, first make sure all split files (.z01, .z02, ..., and the .zip file) are downloaded in the same directory, then extract only the .zip file - it will automatically read the orther parts. If you find this version helpful, please cite the original source: Animesh Basak Chowdhury, Benjamin Tan, Ramesh Karri, & Siddharth Garg. (2022). OpenABC-D: A Large-Scale Dataset For Machine Learning Guided Integrated Circuit Synthesis [Dataset]. Zenodo. https://doi.org/10.48550/arxiv.2110.11292