dns: consistently add hostname
Right now the hostname could in some cases be missed, depending on the libuv error number. This makes sure there the hostname is always added, if available.
This currently relies on https://github.com/nodejs/node/pull/19719 and I am going to rebase the PR as soon as that lands.
Checklist
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make -j4 test
(UNIX), orvcbuild test
(Windows) passes -
tests and/or benchmarks are included -
documentation is changed or added -
commit message follows commit guidelines