QNAME minimization is bypassed with stale zonecut in cache (9.16)

Add test cases for GL #2665 (closed): The QNAME minimization (if enabled) should also occur on the second query, after the RRsets have expired from cache. BIND will still have the entries in cache, but marked stale. These stale entries should not prevent the resolver from minimizing the QNAME. We query for the test domain a.b.stale. in all cases (QNAME minimization off, strict mode, and relaxed mode) and expect it to behave the same the second time we have a stale delegation structure in cache.

(cherry picked from commit 322626ab)

Closes #2665 (closed)