Add pdb id for affected interacting genes with residue-level evidence

The PDB file we format to check if any genes are affected by the splicing events with residue-level evidence should contain PDB IDs. These however get cut out when we format the original file. We should see if we can add the pdb id and maybe be able to add it to the table to display on the web page.

This concerns a raw file downloadable from the original DIGGER website: [Position-specific residue annotations of the PPI](https://www.exbio.wzw.tum.de/digger/download/)