fix(sharing): Adapt share suggestions to match trusted servers configs

[nfebe]

When show_federated_shares_to_trusted_servers_as_internal is enabled but show_federated_shares_as_internal is not, filter federated share suggestions to only include trusted servers. Previously, searching for an email address would suggest non-trusted federated servers.

Resolved: #54511

[susnux]

I do not fully understand how this is possible only on backend side.
Because with "show trusted servers as internal" the search request from the frontend is basically the same, both "internal shares" and "external shares" will search for remote type.

The difference is only that with "show trusted servers as internal" that only trusted servers should be shown in the "internal share" results, while all other remotes should still be listed in "external shares" results

[tobiasKaminsky]

/backport to stable-31

[nfebe]

/compile

[nfebe]

/compile

[nfebe]

/compile

[nfebe]

/compile

[nfebe]

/compile

[backportbot]

The backport to stable-31 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable-31
git pull origin stable-31
# Create the new backport branch
git checkout -b backport/55080/stable-31
# Cherry pick the change from the commit sha1 of the change against the default branch# This might cause conflicts, resolve them
git cherry-pick c1d9e22c c9bb6eed 8c7be09d
# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/55080/stable-31

Error: Failed to clone repository: Failed to create working tree: Preparing worktree (new branch 'backport/55080/stable-31')
fatal: not a valid object name: 'origin/stable-31'

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Learn more about backports at https://docs.nextcloud.com/server/stable/go.php?to=developer-backports.

[nfebe]

/backport to stable32

[nfebe]

/backport to stable31