[server][DBClientUser] Use a defined type to improve readablity and flexibility.
[server][DBClientZabbix] Use a defined type to improve readablity and flexibility.
[server][FaceRest] Use a defined type to improve readablity and flexibility.
[server][VirtualDataStore] Use a defined type to improve readablity and flexibility.
[server][VirtualDataStore] Use a defined type to improve readablity and flexibility.