authentication: adding hostname parameter to ssh method

[danlavu]

Some tests will require to connect using the client hostname instead of localhost, adding this flexibility.

[danlavu]

INFO     2024-12-20 07:03:42,965          client.test Previous command completed with exit code 202
                                                      Output: |
                                                        spawn ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -o PreferredAuthentications=password -o NumberOfPasswordPrompts=1 -l user1 localhost
                                                        KnownHostsCommand-ORDER /usr/bin/sss_ssh_knownhosts localhost failed, status 1

                                                        KnownHostsCommand failed

Ran into the following issue, SSSD/sssd#7664 , I'm sure the host is not up to date, but it bring this to my attention.