Report full via path

When reporting the `via` information for modules on `avail`/`spider`, it would be clearer to see the full via path rather than only the last via part.

On regular output, it means providing the following kind of information:

```
--- modpath (via A > B > C) ---
```

On JSON, it means to change the `via` key to report an array value:

```
"via": ["A", "B", "C"]
```