Context switcher > Store frequently visited project/groups to the DB

This is part of the work to move the frecently visited namespaces to the backend: &11957 (closed).

• Create the server_side_frecent_namespaces feature flag.
• Create the projects_visits and groups_visits DB tables with the following rows:
  • user_id: ID many-to-one relation with a user.
  • entity_id : ID many-to-one relation with a project or group.
  • visited_at : Datetime The item's access date.
• Create the Visitable concern which exposes the necessary methods to check whether a namespace was visited recently.
  • We consider that an item was "accessed" when any of its page is visited, unless a prior access was tracked less than 15 minutes ago.
• Create the TrackNamespaceVisitsWorker which is responsible for tracking users' visits to projects and groups.
• Create API endpoints which the frontend calls to track visits.