Description

It would be nice if users can leave a comment for a specific entity. (e.g., to indicate requests for changes)

Required changes

[ ] discuss whether this feature should be added to the TOP framework
[ ] add schema for comments (comments should have a text, a timestamp, and an author)
[ ] add paths to add, list, and remove comments
[ ] restrict comment creation to users with read permission
[ ] restrict comment deletion to users with write (or manage?) permission