test: increase coverage for net/blocklist

1. test new BlockList with invalid args
Refs: https://coverage.nodejs.org/coverage-f7dd330ba0e7bfa9/lib/internal/blocklist.js.html#L34

2. test addRange with invalid start and end
https://coverage.nodejs.org/coverage-f7dd330ba0e7bfa9/lib/internal/blocklist.js.html#L78

3. test blocklist addSubnet with invalid args
Refs: https://coverage.nodejs.org/coverage-f7dd330ba0e7bfa9/lib/internal/blocklist.js.html#L81

4. test blocklist check with invalid args
Refs: https://coverage.nodejs.org/coverage-f7dd330ba0e7bfa9/lib/internal/blocklist.js.html#L107

5. test util.inspect case
Refs: https://coverage.nodejs.org/coverage-f7dd330ba0e7bfa9/lib/internal/blocklist.js.html#L39

PR-URL: https://github.com/nodejs/node/pull/36405


Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Michael Dawson <midawson@redhat.com>