src/: Pass the wanted query's type code to adns__internal_submit.

This has two effects.  Firstly, we can propagate non-representation bits
(e.g., compatibility flags) from parent to child query.  Secondly, we
can have a single typeinfo handle several different low-level record
types.  The former is going to pay off very soon; the latter will take a
bit longer, but it'll be worth it.

Signed-off-by: Mark Wooding <mdw@distorted.org.uk>