ldap_utils.go had no tests. LdapConvertEntries, LdapSearchAttributes and
LdapIsMemberOf need no server, so cover those three. LdapConnect and
LdapFindAllUsers still do.
Pins what the sync depends on: a field_map naming an attribute the server
does not return yields an empty identifier rather than a missing key.
Group membership stays raw for DN parsing, and the attribute list drops
unset fields and duplicates.
Signed-off-by: clark-ja <37738506+clark-ja@users.noreply.github.com>
