Feature/user db security obj readonly (#2395)

* Allow to set the user db security object to readonly

- Add the default config 
- Deny update on _security if the database is the user db and if the config is to false
- Add unit test

* Allow edits on _users security for the JS test

Co-authored-by: Alexis Côté <popojargo@users.noreply.github.com>
4 files changed