Test fetching PDB entries with extended IDs

[padix-key]

This PR adds a test that checks if extended PDB IDs are supported by fetch().

[codspeed-hq]

CodSpeed Performance Report

Merging #816 will not alter performance

_{Comparing padix-key:extended-id (f009c5c) with main (ac856a2)}

Summary

✅ 59 untouched benchmarks