* Add test case for TXT lookup via CNAME
Signed-off-by: Jonathan Nagy <nagytech@users.noreply.github.com>

* Return HostType of explicit TXT records
Signed-off-by: Jonathan Nagy <nagytech@users.noreply.github.com>

* Adapt TXT method lookup to allow lookup via CNAME
Signed-off-by: Jonathan Nagy <nagytech@users.noreply.github.com>

* Implement lookup of TXT records via CNAME
Signed-off-by: Jonathan Nagy <nagytech@users.noreply.github.com>