Currently Action subclasses have a requiresUnblock method which encodes if this action should be allowed or not when the user is blocked. This creates issues for PermissionManager/Authority since they need to instantiate a UI Action class to find out whether permission check needs to test for user block or not.

Ideally, instead we need to create a new config setting $wgBlockExemptPermissions and deprecate the old mechanism. Looking this up should be extracted into UserBlockManager or into a new service.