Bug: Offline mode doesn't show SystemID or Product

[mallardduck]

The SCC Operator cannot set these values on a Registration currently because it is not included in the Offline Cert.

Once the offline cert is updated to include these details we should save them from the Cert into the Registration object. This will make the offline and online modes more similar once a successful registration is complete.

Blocked by: SUSE/connect-ng#313

[mallardduck]

Removing the milestone as this is dependant on: a) SCC changes, b) SCC API libarary changes and then I can finally make Operator changes.