[1.x] Fixes switch cases namespace resolution

[nunomaduro]

This pull request fixes #78, witch is related to the usage of switch cases cases combined with namespace resolution.

So, prior to this pull request, the following scenario was not possible:

use Laravel\Scout\Searchable;

Route::get('show', function (User|Product $model) {
    switch(true) {
        $user instanceof Searchable: // bug here, because Searchable was not converted to $user instanceof \Laravel\Scout\Searchable;
            return view('search-view');
    return view('regular');
});