[SSH] Rework SSH server

[avano]

• use password auth by default
• when SSH keys are configured, use key-based auth only and disable password auth
• unify classnames, e.g. SshAccount -> SSHAccount
• move docker files to this repo

[mcarlett]

is this ssh client still maintained? I see it has been moved https://mvnrepository.com/artifact/net.schmizz/sshj

net.schmizz » sshj→com.hierynomus » sshj

[avano]

is this ssh client still maintained? I see it has been moved mvnrepository.com/artifact/net.schmizz/sshj

net.schmizz » sshj→com.hierynomus » sshj

i'd say yes, we use the com.hierynomus:sshj dependency, and there are both net.schmizz and com.hierynomus packages: https://github.com/hierynomus/sshj/blob/master/src/main/java/net/schmizz/sshj/SSHClient.java