[9.20] new: dev: Add spatch to detect implicit bool/int/result cast

Detection of implicit cast from a boolean into an int, or an
isc_result_t into a boolean (either in an assignement or return
position).

If such pattern is found, a warning comment is added into the code (and
the CI will fails) so the error can be spotted and manually fixed.

Backport of MR !11095

Merge branch 'backport-colin/cocci-detect-iscresult-int-implicit-casts-9.20' into 'bind-9.20'

See merge request isc-projects/bind9!11237