To achieve read new for {T324907}, the CheckUser tables now store log events in the structured `log_params` format along with a `log_action` and `log_type`. This means that the action text is generated on the fly when showing results of a check.
When reading old, the action text was generated at insert time. This meant that to allow log entries to be shown that have an entry in `wgLogRestrictions` CheckUser needed to in a `newExtraneousContext` give temporary user rights such that the CheckUser code could save the actiontext to the database. Extensions that were sending log entries would add the rights to `wgCheckUserLogAdditionalRights` such that CheckUser could save the actiontext reliably.
The difference means that the config `wgCheckUserLogAdditionalRights` should no longer be needed but also that the actiontext would only be shown if the user has the rights to see the log entry.
As such, this config should be removed along with usages in other extensions.
======Acceptance criteria
* [] Remove `wgCheckUserLogAdditionalRights`