Foreign table id cannot be a foreign key of a base table. But the current code use foreign keys to link object metadata with activities, events... So we will: - create a column without creating a foreign key - add a comment on the table schema so pg_graphql sees it as a foreign key This PR: - refactor a bit object metadata service so the mutation creation is separated into an util - adds the mutation creation for remote object relations - add a new type of mutation to create a comment --------- Co-authored-by: Thomas Trompette <thomast@twenty.com>