fix: trim duplicate search results for external share

[Antreesy]

Resolves

• When deduplicating collaborator results, email shares were not being removed when the same person appeared as a lookup server result.
• Additionally, exact email matches (in the exact bucket) were being ignored entirely due to strict guard condition.

Summary

• Merge exact and non-exact email results before deduplication
• Extend the removal logic to also cover lookup server results
• now email share entry is dropped whenever a federated or lookup match exists for the same person.

TODO

• Test coverage?
• Manual test

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)
• Labels added where applicable (ex: bug/enhancement, 3. to review, feature component)
• Milestone added for target branch/version (ex: 32.x for stable32)

AI (if applicable)

• The content of this PR was partly or fully generated using AI

[n-iv]

Fixes the problem on a very large cluster, thank you

[Antreesy]

/backport to stable34

[Antreesy]

/backport to stable33

[Antreesy]

/backport to stable32