Issue 50875 - Refactor passwordUserAttributes's and passwordBadWords's code
    
    Bug Description: Searches on cn=config takes values with spaces and
    makes multiple attributes out of them. If we set passwordUserAttributes
    to "cn uid givenname", it will transform it in a multi-valued attribute.
    
    Fix Description: Change passwordUserAttributes's and passwordBadWords's type
    to CONFIG_STRING (it was CONFIG_CHARRAY). Add an additional parameter
    to store the array (and use it in pw.c).
    The string and array processing is similar to nsslapd-allowed-sasl-mechanisms.
    Add tests for both attributes.
    
    https://pagure.io/389-ds-base/issue/50875
    
    Reviewed by: mreynolds, tbordaz, firstyear (Thanks!)