fix: dev: Fix resolver SERVFAILs valid queries and crashes on shutdown

After a recent change, recursive queries that need internal retries —
long DNSSEC chains, EDNS or cookie renegotiation, TCP fallback —
started failing with SERVFAIL on lookups that previously succeeded,
and named could also crash on shutdown after such failures.  The
max-recursion-queries default is restored to 100 (its prior value),
and the cleanup bug that caused the shutdown crash is fixed.

Closes https://gitlab.isc.org/isc-projects/bind9/-/issues/5951

Merge branch '5951-resolver-resend-rmessage-leak' into 'security-bind-9.11'

See merge request isc-private/bind9!1027