Feature request: support users’s .ssh/config

Hello and thanks for the amazing work you do on Postico. I hope, this issue tracker is the right place for feature requests.

In our setup we’re connecting to a db via ssh tunnel using ProxyCommand.
Currently I am using [Secure Pipes](https://www.opoet.com/pyro/index.php) as it makes managing tunnels easier. Otherwise I’d have to check/re-establish a tunnel every time after I wake up my laptop.

Would be good if Postico could do one of the 2 things:
- directly support _ProxyCommand_
- support user’s ssh_config. So I could provide a host name alias from there, and server address and other options, including _ProxyCommand_ would be taken from the config

Thanks. Would make life **much** easier for me as now in practice I have to click several more times and use 2 apps (Postico and Secure Pipes) pretty much every time I want to connect to a db.

No file, test, or entry point is named. Begin by identifying where Postico creates SSH connections and how database connections are configured; done means either ProxyCommand works directly or settings from the user’s .ssh/config are honored, including host aliases and related options.

Written by the indexing model from the issue text.