tweak handling of ANY and RRSIG in QTYPE
- advanced users can configure these QTYPEs on Lua level, e.g. option('QTYPE_ANY', true)
- fix handling these QTYPEs, e.g.
- caching: as whole packet only (simple and "safer" here)
- iterator wasn't finding ANY records in answer :-)
- I wanted to disable RRSIG by default, but let's delay that