Added support for AAAA record for coredns and included unit test.
Fixed function names in comments for Google and AWS tests to match
actual test name in this area.
There can be multiple DNS resource records for a given name. They can
vary by type, ttl, rrdata and a number of various other parameters. It
is incorrect to return a single resource record for a given name.
This change updates the Get interface to return multiple records for a given
name and uses this list in the federated service controller to perform
DNS operations.
This will allow us to pass e.g. a ResourceRecordChangeset, rather than a
ResourceRecordChangeset, the parent ResourceRecordSets, and the
grandparent Zone.
Laying the groundwork for simplifying / optimizing the federation logic.
