winbind:varlink: Implement get user record by name

winbind:varlink: Implement get user record by name

$> userdbctl -s org.samba.winbind user AFOREST+user1
Enabled services: org.samba.winbind
   User name: AFOREST+user1
 Disposition: regular
    Login OK: yes
 Password OK: no (none set)
         UID: 21105
         GID: 20513 (unresolvable: No such process)
   Directory: /home/AFOREST/user1
     Storage: classic
       Shell: /bin/bash
   Passwords: none
     Service: org.samba.winbind

$> SYSTEMD_LOG_LEVEL=7 getent -spasswd:systemd passwd AFOREST+user1
varlink: Setting state idle-client
/run/systemd/userdb/org.samba.winbind: Sending message: {"method":"io.systemd.UserDatabase.GetUserRecord","parameters":{"userName":"AFOREST+user1","service":"org.samba.winbind"}}
/run/systemd/userdb/org.samba.winbind: Changing state idle-client → awaiting-reply
/run/systemd/userdb/org.samba.winbind: New incoming message: {"parameters":{"incomplete":false,"record":{"gid":20513,"homeDirectory":"/home/AFOREST/user1","service":"org.samba.winbind","shell":"/bin/bash","uid":21105,"userName":"AFOREST+user1"}}}
/run/systemd/userdb/org.samba.winbind: Changing state awaiting-reply → processing-reply
/run/systemd/userdb/org.samba.winbind: Changing state processing-reply → idle-client
AFOREST+user1:x:21105:20513:AFOREST+user1:/home/AFOREST/user1:/bin/bash

Signed-off-by: Samuel Cabrero <scabrero@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>