[9.20] fix: usr: Stop delv from aborting on a malformed query name

[9.20] fix: usr: Stop delv from aborting on a malformed query name

delv aborts with SIGABRT instead of exiting cleanly when given a query
name that fails wire-format conversion (e.g. a label longer than 63
octets). After this change delv prints the parse error and exits with
a normal failure code.

Closes #5916

Backport of MR !11921

Merge branch 'backport-5916-delv-run-resolve-null-detach-abort-9.20' into 'bind-9.20'

See merge request isc-projects/bind9!11927