[Feature] Create a command that runs camera setup again

If you change your camera, or plug it into a different USB device, you'll get the error:

```
Camera path is not configured correctly, please edit the 'device_path' config value.
```

I suggest a new command for that: `howdy setup` (or any other verb, I don't care about the verb).

It would be nice to run the setup that finds the camera again, it is much simpler than looking through the device path with `ls -l /dev/v4l/by-path/`, as suggested in https://github.com/boltgolt/howdy/issues/533#issuecomment-829116906.

I am aware, from the comment on https://github.com/boltgolt/howdy/issues/767#issuecomment-1475233381 that we can find the setup scripts [here](https://github.com/boltgolt/howdy/blob/master/debian/preinst), but it is also not as easy to do.

Start by reading the setup scripts linked in debian/preinst and trace how camera setup is currently invoked. Define the command entry point and verify that running it repeats camera discovery after a camera or USB-device change, without requiring manual inspection of /dev/v4l/by-path/.

Written by the indexing model from the issue text.