LDAP: when a value for a user/group id is too long, it should be hashed #28653

We have a limit for user and group ids of 64 characters. At the moment, if a value from LDAP that is supposed to be used as such, is longer than this limit, there is no handling. The possibly best thing to do is to hash the id in this case and document this behaviour. As of now it would fail to write to the DB.