Implement full roundtrip for lookup functionality
With TR64 enabled (default), '☺i' was converted to 'xn-- o-oia59s'. The output contains an illegal space and thus could not be decoded any more.
References: #78 (closed) https://gitlab.isc.org/isc-projects/bind9/issues/1610
Reported-by: Chris Malton Fixes #78 (closed)