Mirrored third-party checkpoints

Third-party model checkpoints used by the pipeline.

• faster_rcnn_1_8_132028.pth — 100DoH hand-object detector (handobj_100K+ego) by Dandan Shan et al., from ddshan/hand_object_detector (MIT, license attached). The upstream download link no longer works (see ddshan/hand_object_detector#38), so a copy is hosted here. md5 f0b494c2d38f8773cef15f2573dced45