[BLOCKED] Appliance console copy keys

This copies fetches keys from a remote machine.

Tested workflows in appliance_console (choosing all the prompts)
Tested in cli

Current issue - only works with gem `net-ssh` versions 2.8.0 and 2.8.1
Note: `net-scp` is pretty old, but it works great.
I did notice we pegged `net-ssh` to 2.6.5 for an old version of fog that we are no longer using.
We would need to test our exposure to this gem.
Commit says "add appliance_console Prompt#prompt_for_string..." was it renamed to ask_for_string?  Can you clarify the commit?