Adds sortable behavior to Laravel Eloquent models
Laravel 11 support by @YOzaz
Laravel 10 support by @peterbabic
Laravel 9 support by @christoph-kluge
Laravel 8 support by @SVV-team
Laravel 6 support by @Chrissi2812
Fix getRelatedKey() in BelongsToSortedMany by @tonystatic
Support Laravel 5.7 by @timothyasp and @troydildine
Fix MorphToSortedMany by @ZAZmaster