"Query 3D Beacons" button / dropdown for structure chooser

3d-beacons requires uniprot accessions, so by default only PDBe is queried when none are available.

Opening Structure Chooser for :
1. proteins where some have no uniprot accessions, or uniprot accessions do not have canonical flag set
- need to prompt user to update via Uniprot dbref fetcher

2.Proteins where no uniprot accessions exist
- Provide a filter option that triggers a uniprot dbref fetch followed by 3d-beacons query