This PR adds support for Laravel Folio. Closes #732.

Laravel Folio registers its routes very differently from how Laravel usually handles routes, so unfortunately this is a bit messy. We're more or less doing what Folio's ListCommand is doing, modified for our needs.

Notes:

• We only deal with named Folio routes.
• Folio includes the (undocumented) ability to specify a custom view data variable name for a route parameter (e.g. https://github.com/laravel/folio/blob/master/tests/Unit/ModelBindingTest.php#L114). Ziggy will use these custom view data variable names as the route parameter names if they're present, because this is what Folio does internally and we would have to anyway so that we avoid duplicate parameter names.