Add support for negative DNS caching in the DNS Lookup data adaptor

Add support negative caching according to the domain's SOA TTL policy for the DNS Lookup data adaptor.

Use Case: When a DNS record is queried from a name server, but the record does not exist, the fact that the record does not exist is only valid for a specific amount of time (defined be the SOA TTL policy). This indicates when the next request for the same record should be attempted to see if it exists again.

Currently, the DNS Lookup adaptor would cache the negative (non-existent) result for as long as the 'Expire after' setting indicates in the adaptor's cache. Once implemented, the SOA TTL would be used instead.