Display pubkey better hash and add rate

[nbeguier]

keys are not display properly :

    "ssh_key_hash": "2048 e8:47:77:a6:ea:aa:7d:26:67:24:ba:3a:52:b6:3f:ce ", 

    "ssh_key_hash": "2048 SHA256:R8NwvNikoqVR9DMwvNikoqVR9DdOSwvNikoqVR9D roberto@roberto-ThinkPad-T470p (RSA)\n", 

    "ssh_key_hash": "256 SHA256:hf44FmQ8YdbeEdO+u7geOKv", 

It could be better to split this into category :

• DSA (weakest)
• RSA (standard)
• ECDSA (better)
• Ed25519 (strongest but not suported on old OS)

and show the length.

Why not add a rate to help the admin to validate a key

[nbeguier]

1.6.0 server