.ssh / client config management helper

[XavierChanth]

I would like to add a dart binary which can config the following types of config:

• Can add certain device entries to .ssh/config (possibly including port forwarding)
• Can read config from the devices sharing to it (these cannot be modified, but maybe we can support a reference to this which can be overridden with additional configs*)
• Can list all configs for you to interact with
• Can import / export config to JSON files
• Can edit / upload / download configs from the atServer

I'd also like to redesign the config to be more modular across all platforms...

Something like:

{
"key": "..." // (optional) atkey containing the base config - use case: want to override config shared from a device
"to": "@client",
"from": "@device",
"sshnp": {...}, // (optional) if sshnp connection
"npt": {...}, // (optional) if npt connection
// ... some other shared things between npt / sshnp can be in the root
}

[XavierChanth]

@gkc @cconstab what do you think?

[XavierChanth]

Changing to 2SP to add a tutorial to the noports docs.