[9.20] chg: test: Replace dns.query module with isctest.query
requested to merge backport-mnowak/convert-dns-query-udp-and-tcp-to-isctest-query-9.20 into bind-9.20
The dns.query.udp and dns.query.tcp methods are prone to timeouts; their isctest.query equivalents should be used in system tests instead.
Backport of MR !9560 (merged)