Rewrite FriendlyId::SlugDecorator to Module.prepend
Rewrite FriendlyId::SlugDecorator to Module.prepend

This fixes autoloading issues with Rails 6 and Zeitwerk trying to autoload `FriendlyId::SlugDecorator` constant

ayb/spree,ayb/spree,imella/spree,ayb/spree,imella/spree,ayb/spree,imella/spree