WIP: contrib/kresd: log SERVFAILs by default
This change would generate about 120 MB of gzipped logs across the 7 respdiff test cases we currently have. I don't want to upload these as gitlab artifcats, so I'm postponing this change until we're able to handle (verbose) logs differently in our CI.
Depends on https://gitlab.nic.cz/knot/knot-resolver-ansible/-/issues/3