Fix tests for parent-centric resolver behavior

Fix tests for parent-centric resolver behavior

In 'additional', pre-cache the A RRset for ns1.rt.example so the
additional-data handling in the cache can be tested; previously this
was cached as part of resolution, but now must be queried explicitly.

In 'cookie', pre-cache an NS to prevent a QMIN query from distorting
log results and causing a test failure.

In 'resolver', increase the expected query count in the timeout test.