Makes builder to respect ssh_proxy_* configuration

[sparshev]

In general those changes allows us to use proxy in order to check the address given it by vmware dhcpd. The changes are rip-off of the original plugin SDK: https://github.com/hashicorp/packer-plugin-sdk/blob/main/communicator/step_connect_ssh.go#L109

The catch here: in general under perfect conditions this change are not needed, because VMware Fusion/workstation connects locally, but if we're using corporate VPN which redirects all the traffic (but localhost) to the corporate network - we can't reach the VM anymore. I found just one way to do so relatively simple: by using SO_DONTROUTE which skips the routing table and allows to communicate directly to the interfaces. So any simple (python/go) proxy with remote.setsockopt(socket.SOL_SOCKET, socket.SO_DONTROUTE, 1) will allow to communicate to VM. In order to not break any compatibility proxy interface looks good - after the packer verified the IP address we can move on to ansible provisioner and through the packer provided proxy (or http_proxy env variable) control the transport to the VM.

[azr]

Nice one, this LGTM, I wish we could be re-using that code instead of copying it !