Nickname path

Using `open --url postico://...` with version 2.1 in an enterprise environment.
Would it be possible to make `--nickname` support paths? Currently `/` just gets applied to the name.

For example, to create `Awesome Database` **under** `Production`:
```
open --url postico://... --nickname Production/Awesome Database
```

Another option would be a new `--directory` or `--path` argument.

Start by locating the command-line handling for `open --url` and the `--nickname` argument. Trace how the nickname is interpreted, then verify that a slash-separated value such as `Production/Awesome Database` creates the requested nested path or assess the alternative path argument; the issue is done when the chosen behavior works in the enterprise use case.

Written by the indexing model from the issue text.