Add supprot for create a cyborg admin client when no user token is present.

When we resume guest state with accelerator bound, we should pass
the accel_info when the guest hard reboot. In the process of getting accel info, we should add no user token auth to
get Cyborg client by cyborg user password configured, or the VM will be set error because of lost communication with Cyborg.
So add user/project CONF with admin role at cyborg group, and when determine context is_admin and without token, do authenticaion with user/project info to call cyborg api.