Provide ability to see (remotely) last applied replication segment using services API and in fbsvcmgr output

[pavel-zotov]

Please provide a way to obtain number of segment that has been applied to replica, e.g.:

C:\FB\50SS>fbsvcmgr service_mgr <remoye_ip>/<port>:service_mgr action_db_stats dbname db_repl_alias sts_replica_status

Database "C:\FB\50SS\examples\empbuild\qa_replication\db_repl.fdb"
Gstat execution time Wed Oct 22 14:41:26 2025

Database header page information:
        ...
        Attributes              read-only replica
...
    Replica status:
        Last sequence: 3 (complete)
        Active transactions: 0
        *END*
Gstat completion time Wed Oct 22 14:41:26 2025