ApiConfig: avoid using pbs_config::backup_user()
CommandoSocket: avoid using pbs_config::backup_user()
FileLogger: avoid using pbs_config::backup_user()
- use atomic_open_or_create_file()
Auth Trait: moved definitions to proxmox-rest-server/src/lib.rs
- removed CachedUserInfo patrameter
- return user as String (not Authid)
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>