Instead of relying on user input values, we use the DN value returned by
the LDAP server.

This handles cases like when a mapping is set on a DN value
`uid=svc.algorithm,OU=swengg,DC=min,DC=io` with a user input value (with
unicode variation) of `uid=svc﹒algorithm,OU=swengg,DC=min,DC=io`. The
LDAP server on lookup of this DN returns the normalized value where the
unicode dot character `SMALL FULL STOP` (in the user input), gets
replaced with regular full stop.