Models/servers are not persisted between launches

[sejmann]

I haven't been able to get server configs to persist between launches of PicoMLXServer, and have had to recreate each server each time. I did briefly try to look through the code, and saw UserDefaults was used for preferences, but not (at least not obviously) for servers, and confirmed the contents of ~/Library/Preferences/com.starlingprotocol.PicoMLXServer.plist did not contain model/server info. Nothing stored in ~/Library/Application Support, either.

[ronaldmannak]

I'm reworking server management in the next version. Will add persistency.