Show fingerprint for user SSH keys

Feature request that was originally posted by Nobuto Murata

MAAS can manage SSH keys for a user, but it doesn’t show the content of public keys nor fingerprint. That makes key management hard like users are not able to distinguish keys precisely other than the comment.

Would be nice to a capability to reveal either the full content of a pub key or a fingerprint (ssh-keygen -l).

For the record, an API request can reveal the full content.

$ maas admin sshkeys read
Machine-readable output follows:
        "key": "ssh-ed25519 (...) ubuntu@maas",
        "id": 1,
        "keysource": "",
        "resource_uri": "/MAAS/api/2.0/account/prefs/sshkeys/1/"