feat(bindings): Allow user identities to only be fetched from storage

[poljar]

This closes #5867.

• Public API changes documented in changelogs (optional)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.60%. Comparing base (9ab886f) to head (261bd16).
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #5870   +/-   ##
=======================================
  Coverage   88.59%   88.60%           
=======================================
  Files         363      363           
  Lines      102888   102888           
  Branches   102888   102888           
=======================================
+ Hits        91153    91162    +9     
+ Misses       7496     7484   -12     
- Partials     4239     4242    +3     

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[codspeed-hq]

CodSpeed Performance Report

Merging #5870 will not alter performance

_{Comparing poljar/bindings/user-identity-local-only (261bd16) with main (9ab886f)}

Summary

✅ 50 untouched