This fixes `clan ssh` with the `--json` and `--png` flags.
It will now correctly use the actual fields that are present in the
generated json.
- probes if the ports are accessible
- if accessible will attempt a single ssh connection with the provided
password, in order to not spam ssh attempts
Fixes#1177
In this directory we generate all the files that we need to load nixpkgs.
This seems more robust than all those environment variables that may or not may be set.
