Affected: Maven: io.netty:netty-resolver-dns

### Summary Netty's DnsResolveContext fails to validate the origin (bailiwick) of CNAME records in DNS responses.

### Details In `io.netty.resolver.dns.DnsResolveContext#buildAliasMap`, the resolver processes the ANSWER section of a DNS response and blindly caches all CNAME records it finds.

According to https://datatracker.ietf.org/doc/html/rfc5452#section-6

``` Care must be taken to only accept data if it is known that the originator is authoritative for the QNAME or a parent of the QNAME. One very simple way to achieve this is to only accept data if it is part of the domain for which the query was intended. ```

### Impact DNS Cache Poisoning (Bailiwick Bypass). Any application using Netty's DNS resolver is impacted.