server: Resolve aliases in set_locked (backport to 0.6)

[rebizzz]

Backports commit 4671c6a to the 0.6 branch.

Right now on 0.6, unlocking or locking /org/freedesktop/secrets/aliases/default spams:
WARN oo7_daemon::service: Object: /org/freedesktop/secrets/aliases/default does not exist.

This happens because set_locked compares literal object paths instead of resolving aliases first, and the warn log sits inside the collection loop.

Backports resolve_alias into set_locked and moves the warning outside the loop, matching what is on main.

[bilelmoussaoui]

It should be cherry picked if you want it backported but in any case, 0.6 release was not ready in any mean, you should bump to 0.7.0-beta, the stable release will be done in few days

[rebizzz]

Thanks for the heads-up! Closing this since 0.7.0 stable is releasing soon, so we will bump to 0.7.0 then.