Update facade methods to use Illuminate collection type hints

[caendesilva]

This seems to be better supported by PhpStorm when reading the generics.

    /**
     * Get a collection of all pages, parsed into page models.
     *
     * @return \Illuminate\Support\Collection<\Hyde\Pages\Concerns\HydePage>
     */
    public static function all(): PageCollection
    {
        return Facades\Pages::getPages(static::class);
    }