This is basically
<af7ce9b8ed>,
but with support for deploying locally.
This failed to install secrets to `/var/lib/sops-nix`. That's because
our `LocalHost` didn't have support for sudo yet. I fixed that.
Motivation: local builds and deployments without ssh
Add a new interface `Host` which is implemented bei either `Remote` or `Localhost`
This simplifies all interactions with hosts. THe caller does ot need to know if the Host is remote or local in mot cases anymore
