default checkpoint path for PEM needs to be updated

[SajjadPSavoji]

the default path for PEM checkpoint in SAM-6D/Pose_Estimation_Model/test_bop.py is checkpoint = os.path.join(cfg.log_dir, 'checkpoint_iter' + str(cfg.test_iter).zfill(6) + '.pth'). But after setting up the repo weight are downloaded under the checkpoints not logs.

Modify by the following:
default_checkpoint_path = os.path.join(BASE_DIR, 'checkpoints', 'sam-6d-pem-base.pth')