in af2_initial_guess/predict.py PDB mode skips checkpoints due to inconsistent naming in self.finished_structs

[xuqiqin]

When using pdb as input in af2_binder_design, the checkpoints are skipped due to a mismatch in naming conventions. The full pdb name is added to self.finished_structs, but the checkpoint check is performed using the tag name. Storing tag name to self.finished_structs fix the issue.