text: Title: Remove RRset write-support for locked users
  Body: Currently, locked users can write RRsets to the application database. Only upon unlocking the user account, these RRsets will be propagated to pdns.
  
  This leads to various difficulties regarding validation and consistency, see https://github.com/PowerDNS/pdns/issues/7565#issuecomment-476397025
  
  As the benefit of the feature is questionable, nobody will miss it if it's not there, and it even may lead to confusion ("My PATCH was successful, but changes don't get propagated?!"), it is better to remove the feature.