Only render required zones in config for nsec3 tests

Only render required zones in config for nsec3 tests

When all zones are configured, regardless of whether the test module
actually uses them, it makes debugging the logs needlessly more
complicated, as there is a bunch of stuff going on that is completely
unrelated to the test.

Define a list of tested zones in each test module and only render the
named.conf with those zones defined.

(cherry picked from commit 66e4146a88c4de2b0881e29ff269f01f6658d376)