check AAAA and CNAME for duplicate records. fixes #5623

interface/web/dns/dns_aaaa_edit.php

interface/web/dns/dns_cname_edit.php

interface/web/dns/lib/lang/ar_dns_a.lng

interface/web/dns/lib/lang/ar_dns_aaaa.lng

interface/web/dns/lib/lang/bg_dns_aaaa.lng

interface/web/dns/lib/lang/br_dns_aaaa.lng

interface/web/dns/lib/lang/ca_dns_aaaa.lng

interface/web/dns/lib/lang/cz_dns_aaaa.lng

interface/web/dns/lib/lang/de_dns_aaaa.lng

interface/web/dns/lib/lang/dk_dns_aaaa.lng

interface/web/dns/lib/lang/el_dns_aaaa.lng

interface/web/dns/lib/lang/en_dns_a.lng

interface/web/dns/lib/lang/en_dns_aaaa.lng

interface/web/dns/lib/lang/es_dns_aaaa.lng

interface/web/dns/lib/lang/fi_dns_aaaa.lng

interface/web/dns/lib/lang/fr_dns_aaaa.lng

interface/web/dns/lib/lang/hr_dns_aaaa.lng

interface/web/dns/lib/lang/hu_dns_a.lng

interface/web/dns/lib/lang/hu_dns_aaaa.lng

interface/web/dns/lib/lang/id_dns_aaaa.lng