Allow all agent sync from ldap to db

[pboguslawski]

Proposed change

This mod introduces cli command

 otrs.Console.pl Admin::User::SyncAll [--count ...] [--invalidate-missing]

that allows to synchronize all agents from specified backend.

Specify --count X to synchronize from AuthSyncBackendX configured
in Config.pm (AuthSyncBackend will be used if --count parameter
is not specified).

Adding --invalidate-missing will force all valid users in DB
that are not present in LDAP backend to be invalidated on sync.

This mod introduces also
AuthSyncModule::LDAP::AlwaysFilterReturnsOnlyValidUsers option; when set,
invalid users in DB will be changed to valid when synchronized from LDAP
to DB.

Type of change

• '1 - 🚀 feature' - New feature (which adds functionality to an existing integration)

Additional information

Author-Change-Id: IB#1110475

Checklist

• The code change is tested and works locally.(❗)
• There is no commented out code in this PR.(❕)
• You improved or added new unit tests.(❕)
• Local ZnunyCodePolicy passed.(❕)
• Local UnitTests / Selenium passed.(❕)
• GitHub workflow CI (UnitTests / Selenium) passed.(❗)